Instead of relying on _CLIENT_VARIABLES default park configuration, configure depending on model

[pellcorp]

So when copying start_end.cfg, also set these variables in _CLIENT_VARIABLES:

variable_use_custom_pos   : False ; use custom park coordinates for x,y [True/False]
variable_custom_park_x    : 0.0   ; custom x position; value must be within your defined min and max of X
variable_custom_park_y    : 0.0   ; custom y position; value must be within your defined min and max of Y

Set variable_use_custom_pos to True
Set the variable_custom_park_x to be printer.toolhead.axis_maximum.x - 10.0
Set the variable_custom_park_y to be printer.toolhead.axis_maximum.y - 10.0