low_brightness_threshold causes Shellys to immediately overheat

[blefevre]

I've got a number of Shellys flashed with ESPHome and wired up to 240v with no neutral wire and the Shelly bypass.
The low_brightness_threshold setting is causing my downlights to emit a buzzing sound and for the temperature of the Shelly to spike up above 90C in a under a minute (at which point ESPHome shuts it off).

This seems to occur for any value of low_brightness_threshold regardless of what brightness the lights are turned on at, but the buzzing is worse the higher the low_brightness_threshold value is.

I've tried versions 51.6, 51.7, and 51.7 with SHD_NO_NEUTRAL defined.