Re the rotation auto-detection not working, I’m afraid this is another one where we will need Tridge to investigate (he wrote this part of the compass calibration). What we will need to investigate is a tlog from the ground station during the calibration. So you could for example set the COMPASS_ORIENT back to zero and re-do the calibration. Then disconnect, shut-down the GCS and grab the tlog and post it somewhere. This thread is getting quite long so it might be good to create a new thread under Copter-4.0.
Sorry for the slow response but thanks for the report. We think we have a fix coming shortly in -rc5 that will resolve the hdop reporting for the 2nd GPS so if you could retry with -rc5 when it’s out that would be greatly appreciated!
Thanks for the quick fix!