First of all, thank you for contributing.
Yes, I've seen Phase One knowledge base entry- I think they meant CFE lenses, not "CFA", which makes sense.
Funnily enough I took the same path of reasoning- if there is an applicable solution to the problem, Kapture Group has one
I contacted Keith a few hours ago and in fact there are two solutions- OneShot Cable Release for Hasselblad 200 and 2000 bodies and the multishot cable release. Both are a bit workaround but it's as good as it gets: with OneShot cable you need to press / release it once slightly before taking the exposure- this wakes up the back. Then you press the trigger deep and you have to hold it until the shutter is closed. Multishot gives you freedom of triggering the exposure (no additional sync / trigger cables, just to control unit for the back), but the operation is a bit awkward- you press the 'wake' button, then you press 'capture' button, then you take the photo with the camera trigger and after the exposure ends, you click 'wake' button again to switch your P1 back to standby/sleep mode.
So that would be it- there still is one option to check, though less probable one- that Hasselblad is capable ot adjusting the camera signals to make the sync with P1 back possible. I've been told by Keith that there would be a problem with curtain sync signal (wake up signal syncing is easy peasy). Anyway, if there is a Hassy service route to follow, I'll update this thread.
Fred, thanks for taking your time to research this!