Thanks for all the replies. I compared the specs between the 6a and 7 (especially the camera) a bit more, they seem to be pretty close (and camera-wise way better than my FP4). Waiting for the 7a for the additional year of support, which is not really a year more since the 6a still has 4.5 years atm, is not something I would want. Therefore I dropped by the store on my way home and picked up a 6a :-)
@[deleted]: the FP4 is quite nice and good, but it's on Android 12 and has all the google stuff on it.. Otherwise it is a good phone and I really like the concept.