In the RCgroup.com forum was a clear statement of the Spektrum Dev Team, there will be NO updates for the DX8gen1 anymore.
And thank you for the offer, doing an "extra homework" for me, I appreciate this very much.
I checked on eBay this weekend for a used gen2 TX and found a DX7G2 for a good price as a problem solver.
Beside the DX8 I have a DX7s as a spare and once in awhile as student TX.
I will now sell this radio and install all my helis and planes on the DX7G2 and enjoy the updated telemetry.
All my camera multicopters stay on the DX8G1 since I have TM1000 moduls or OSD (or both) for telemetrie readings on those big birds and I need the 8 channels.
At the end I will finally have enough model slots. All 30 slots on my DX8 where notoriously occupied, no space for variants.
Best regards
Kluftinger