ROS1 Mavros global_position plugin not publishing fused global position topics unless number of satellites >= 15

[DARKMOONlite]

In my ros1 & px4 project I've experienced that mavros only publishes the fused global position topics ~/global, ~/local, ~/rel_alt & ~/compass_hdg if the number of satellites visible is greater or equal to 15, despite correctly interpreting the mavlink data which is also getting published on the raw/fix topic.
Despite being in a relatively large field near a lake, during my flight tests if the weather is clear and I'm lucky I can sometimes get 15-20 visible satellites, however on cloudy days or just 'bad' days in general, I usually hover around 10 satellites with a 1 - 1.5 hdop/vdop. I'm wondering if this is desired behaviour or if I'm missing something, as I've read through the documentation and the global_position.cpp file, none of which state a required number of satellites beyond that of px4's internal required default 6 satellites in order to take off. Not only does my code expect msgs over the ~/global topic but also it expects a transform being published between the map and base_link frames which again is only published to /tf when the number of visible satellites >=15. For the time being I'm going to create a new node that reads the incoming msgs from the ~/raw/fix topic and forward it to the ~/global topic and /tf if the number of visible satellites is under 15 satellites, if that's not a good solution then I am all ears for a better stopgap or permanent fix.

Below is my config file that and pluginlists files I'm passing to mavros. Any guidance or help would be great. If i learn any more in the following days/weeks I'll publish here for posterity.

plugin_blacklist: # https://github.com/mavlink/mavros/tree/master/mavros_extras
  - 3dr_radio
  - actuator_control
  - adsb
  - cam_imu_sync
  - cellular_status
  - distance_sensor
  - esc_status
  - esc_telemtery
  - esc_telemetry
  - ftp
  - geofence
  - gps_rtk
  - guided_target
  - image_pub
  - log_transfer
  - mag_calibration_status
  - manual_control
  - mocap_pose_estimate
  - mount_control
  - nav_controller_output
  - obstacle_distance
  - play_tune
  - px4flow
  - rallypoint
  - rangefinder
  - rc_io
  - safety_area
  - terrain
  - tunnel
  - vibration
  - vision_pose_estimate
  - vision_speed_estimate
  - wheel_odometry
  - wind_estimation
  - fake_gps

plugin_whitelist:
- 'sys_*' # this needs to be enabled for mavros to work
- 'setpoint_*' # loads all the setpoint plugins to allow for setting desitinations
- altitude
- camera
- command
- companion_process_status
- debug_value
- gps_input
- gps_status
#- guided_target # removed to solve the `PositionTargetGlobal failed because no origin` error, 
- hil
- home_position
- imu
- local_position
- odom # from mavros_extras https://github.com/mavlink/mavros/blob/master/mavros_extras/src/plugins/odom.cpp
- onboard_computer_status
- param
- trajectory
- waypoint
- heartbeat_status

# Common configuration for PX4 autopilot
#
# node:
startup_px4_usb_quirk: false

# --- system plugins ---

# sys_status & sys_time connection options
conn:
  heartbeat_rate: 1.0    # send heartbeat rate in Hertz
  timeout: 10.0          # heartbeat timeout in seconds
  timesync_rate: 0.0 #10.0    # TIMESYNC rate in Hertz (feature disabled if 0.0)
  system_time_rate: 1.0  # send system time to FCU rate in Hertz (disabled if 0.0)

# sys_status
sys:
  min_voltage: 10.0   # diagnostics min voltage, use a vector i.e. [16.2, 16.0] for multiple batteries, up-to 10 are supported
                      # to achieve the same on a ROS launch file do: <rosparam param="sys/min_voltage">[16.2, 16.0]</rosparam>
  disable_diag: false # disable all sys_status diagnostics, except heartbeat

# sys_time
time:
  time_ref_source: "fcu"  # time_reference source
  timesync_mode: MAVLINK
  timesync_avg_alpha: 0.6 # timesync averaging factor

# --- mavros plugins (alphabetical order) ---

# 3dr_radio
tdr_radio:
  low_rssi: 40  # raw rssi lower level for diagnostics

# actuator_control
# None

# command
cmd:
  use_comp_id_system_control: false # quirk for some old FCUs

# dummy
# None

# ftp
# None

# global_position
global_position:
  frame_id: "map"             # origin frame
  child_frame_id: "base_link" # body-fixed frame
  rot_covariance: 99999.0   # covariance for attitude?
  gps_uere: 1.0             # User Equivalent Range Error (UERE) of GPS sensor (m)
  use_relative_alt: true    # use relative altitude for local coordinates
  tf:
    send: true             # send TF?
    frame_id: "map"  # TF frame_id
    global_frame_id: "earth"  # TF earth frame_id
    child_frame_id: "base_link" # TF child_frame_id

# imu_pub
imu:
  frame_id: "odom"
  # need find actual values
  linear_acceleration_stdev: 0.0003
  angular_velocity_stdev: 0.0003490659 // 0.02 degrees
  orientation_stdev: 1.0
  magnetic_stdev: 0.0

# local_position
local_position:
  frame_id: "map"
  tf:
    send: true
    frame_id: "map"
    child_frame_id: "odom"
    send_fcu: false

# param
# None, used for FCU params

# rc_io
# None

# safety_area
safety_area:
  p1: {x:  1.0, y:  1.0, z:  1.0}
  p2: {x: -1.0, y: -1.0, z: -1.0}

# setpoint_accel
setpoint_accel:
  send_force: false

# setpoint_attitude
setpoint_attitude:
  reverse_thrust: false     # allow reversed thrust
  use_quaternion: false     # enable PoseStamped topic subscriber
  tf:
    listen: false           # enable tf listener (disable topic subscribers)
    frame_id: "map"
    child_frame_id: "target_attitude"
    rate_limit: 50.0

setpoint_raw:
  thrust_scaling: 1.0       # used in setpoint_raw attitude callback.
  # Note: PX4 expects normalized thrust values between 0 and 1, which means that
  # the scaling needs to be unitary and the inputs should be 0..1 as well.

# setpoint_position
setpoint_position:
  tf:
    listen: false           # enable tf listener (disable topic subscribers)
    frame_id: "map"
    child_frame_id: "target_position"
    rate_limit: 50.0
  mav_frame: LOCAL_NED

# setpoint_velocity
setpoint_velocity:
  mav_frame: LOCAL_NED

# vfr_hud
# None

# waypoint
mission:
  pull_after_gcs: true  # update mission if gcs updates
  use_mission_item_int: true # use the MISSION_ITEM_INT message instead of MISSION_ITEM
                             # for uploading waypoints to FCU

# --- mavros extras plugins (same order) ---

# adsb
# None

# debug_value
# None

# distance_sensor
## Currently available orientations:
#    Check http://wiki.ros.org/mavros/Enumerations
##
distance_sensor:
  hrlv_ez4_pub:
    id: 0
    frame_id: "hrlv_ez4_sonar"
    orientation: PITCH_270 # RPY:{0.0, 270.0, 0.0} - downward-facing
    field_of_view: 0.0  # XXX TODO
    send_tf: true
    sensor_position: {x:  0.0, y:  0.0, z:  -0.1}
  lidarlite_pub:
    id: 1
    frame_id: "lidarlite_laser"
    orientation: PITCH_270
    field_of_view: 0.0  # XXX TODO
    send_tf: true
    sensor_position: {x:  0.0, y:  0.0, z:  -0.1}
  sonar_1_sub:
    subscriber: true
    id: 2
    orientation: PITCH_270
    horizontal_fov_ratio: 1.0   # horizontal_fov = horizontal_fov_ratio * msg.field_of_view
    vertical_fov_ratio: 1.0     # vertical_fov = vertical_fov_ratio * msg.field_of_view
    # custom_orientation:       # Used for orientation == CUSTOM
    #   roll: 0
    #   pitch: 270
    #   yaw: 0
  laser_1_sub:
    subscriber: true
    id: 3
    orientation: PITCH_270

# image_pub
image:
  frame_id: "px4flow"

# fake_gps
fake_gps:
  # select data source
  use_mocap: true         # ~mocap/pose
  mocap_transform: true   # ~mocap/tf instead of pose
  use_vision: false       # ~vision (pose)
  # origin (default: Zürich)
  geo_origin:
    lat: 47.3667          # latitude [degrees]
    lon: 8.5500           # longitude [degrees]
    alt: 408.0            # altitude (height over the WGS-84 ellipsoid) [meters]
  eph: 2.0
  epv: 2.0
  satellites_visible: 5   # virtual number of visible satellites
  fix_type: 3             # type of GPS fix (default: 3D)
  tf:
    listen: false
    send: true           # send TF?
    frame_id: "map"       # TF frame_id
    child_frame_id: "fix" # TF child_frame_id
    rate_limit: 10.0      # TF rate
  gps_rate: 5.0           # GPS data publishing rate

# landing_target
landing_target:
  listen_lt: false
  mav_frame: "LOCAL_NED"
  land_target_type: "VISION_FIDUCIAL"
  image:
    width: 640            # [pixels]
    height: 480
  camera:
    fov_x: 2.0071286398   # default: 115 [degrees]
    fov_y: 2.0071286398
  tf:
    send: true
    listen: false
    frame_id: "landing_target"
    child_frame_id: "camera_center"
    rate_limit: 10.0
  target_size: {x:  0.3, y:  0.3}

# mocap_pose_estimate
mocap:
  # select mocap source
  use_tf: false   # ~mocap/tf
  use_pose: true  # ~mocap/pose

# mount_control
mount:
  debounce_s: 4.0
  err_threshold_deg: 10.0
  negate_measured_roll: false
  negate_measured_pitch: false
  negate_measured_yaw: false

# odom
odometry:
  fcu:
    odom_parent_id_des: "odom"    # desired parent frame rotation of the FCU's odometry
    odom_child_id_des: "base_link"    # desired child frame rotation of the FCU's odometry

# px4flow
px4flow:
  frame_id: "px4flow"
  ranger_fov: 0.118682      # 6.8 degrees at 5 meters, 31 degrees at 1 meter
  ranger_min_range: 0.3     # meters
  ranger_max_range: 5.0     # meters

# vision_pose_estimate
vision_pose:
  tf:
    listen: false           # enable tf listener (disable topic subscribers)
    frame_id: "odom"
    child_frame_id: "vision_estimate"
    rate_limit: 10.0

# vision_speed_estimate
vision_speed:
  listen_twist: true    # enable listen to twist topic, else listen to vec3d topic
  twist_cov: true       # enable listen to twist with covariance topic

# vibration
vibration:
  frame_id: "base_link"

# wheel_odometry
wheel_odometry:
  count: 2           # number of wheels to compute odometry
  use_rpm: false     # use wheel's RPM instead of cumulative distance to compute odometry
  wheel0: {x: 0.0, y: -0.15, radius: 0.05} # x-, y-offset (m,NED) and radius (m)
  wheel1: {x: 0.0, y:  0.15, radius: 0.05} # x-, y-offset (m,NED) and radius (m)
  send_raw: true              # send wheel's RPM and cumulative distance (~/wheel_odometry/rpm, ~/wheel_odometry/distance)
  send_twist: false           # send geometry_msgs/TwistWithCovarianceStamped instead of nav_msgs/Odometry
  frame_id: "odom"             # origin frame
  child_frame_id: "base_link" # body-fixed frame
  vel_error: 0.1              # wheel velocity measurement error 1-std (m/s)
  tf:
    send: false
    frame_id: "odom"
    child_frame_id: "base_link"

# camera
camera:
  frame_id: "base_link"

[vooon]

Check your FC config. If the autopilot not sending global position - how can mavros do?