"Your decision obviously is based on your assumption that the Pixmini.being unreliable/buggy caused the bad AHRS. It's the other way around.. The bad AHRS is a feature of APM 3.3x which not as reliable yet as 3.2x is. So actually you needed …"
"The heading feed starting only after having a 3D sat. fix is by design in MavLink_FrSkySPort-s-c-l-v-rc-opentx2.1
This is done in FrSkySPortTelemetry.ino line 390 with " if(ap_fixtype>=3)".
To get around this limitation you need only to add …"