A little update: the PowerBoard V2 schematics (see public-file section here), ironing out some shortcomings, is ready.
Currently I'm abroad for the job I'm making from my living from - so the next update will take some time. This wil be the V2 schematics of the mainboard containing the Compute Module 3.
So far die V1 prototypes are doing mostly fine. I tried to get a small research-grant to give me more time and money for spending more time ob the BeeStalker, but that was not granted due to shortage of public money. But actually 2 research institues are very interested and give this project a try.