Here's the GCS config needed for PositionHold and ReturnToHome with a Seppuku with an external compass:
Magnetometer: External HMC5983
Ext. Mag. Orientation: Top0degCW (if your compass points the direction of the arrow)
Head over to the attitude page and perform a 6 point calibration on the Magnetometer:
If the calibration completes successfully, It will display something like:
Magnetometer bias, in [mG]: x=8.23815 , y=-90.6005 , z=833.879
Magnetometer scale, in [-]: x=1.29048 , y=1.34727 , z=1.43503
While on the Attitude page, click on the "Filter Settings" Tab. You will need to configure the "Attitude Algorithm" and "Navigation Algorithm" or there will be an error on the "atti" indicator letting you know it's not happy. I've tested with INSOutdoor/INS, and am playing with other combinations to see what else works and how well.
On the "modules tab", enable "VTOL Path Follower module. The GPS module should be automatically configured when configuring the GPS on the "Hardware Tab"
Before going much further, it is a good idea to do a quick sanity test making sure that Altitude hold flight mode works as expected. With the Inconceivable release, it is no longer necessary to enable the Althold module. There is some config done automatically when autotuning. Fine tuning can be done in the object browser AltitudeHoldSettings. By default, dRonin does not have Throttle control (altitude control) enabled in the VtolPathFollwerSettings. If altitude hold mode flies correctly, it is safe to enable this for use by the Nav flight modes.
After changing the value to "TRUE", send and save it to the FC.
Test Position hold out at a location with plenty of room. If it passes the test without much wandering, it should be safe to move on to testing ReturnToHome.
REMEMBER!: If you do not explicitly set Home Position in UAVO, GCS, or the FPV Menu, it will be where it initially acquires a 3D GPS fix after supplying power.