Sorry but i don't think that AMD will release any driver update for non GCN GPUs in future.
They decided to completely stop support for such GPUs
You can install second OS on another logical disk or another HDD and use one system for work(15.7.1 driver) and another system for games(16.2.1 driver)
Ok. I did some tinkering with the drivers and found out that the .inf files in the beta drivers had opencl related .dll:s commented out so they would not be installed. Got the computing working by removing the ;; signs before the .dll:s, cleaned existing drivers from my system, reinstalled the drivers and just to be sure copied all opencl related files that should be inside system32 and syswow64 folders by hand in safe mode. I'm not absolutelu sure which of the thins corrected the problem but I'm currently folding with the newer set of drivers. Even Fallout works now without corrupted graphics and flickering.
I'm sure that the work required to fix these god forsaken drivers would take approximately 5 minutes from an experienced amd engineer (hell, I was able to do it on my own!!)
If some AMD engineer reads this I sincerely hope that you take some pride on the work that you do and fix the fricking drivers!
I suspect someone is not interested in further use of non GCN cards
It is not a technical matter. Just pure business
Glad you are found a quite elegant solution