ON1 Photo RAW 2020.5 seems to be running fine, though obviously I haven't had a chance to test everything.
Affinity Photo 1.8.6 loads and runs OK but I haven't had time to do anything much with it yet. The same with Luminar 4.
PhotoSync 4.0 works fine transferring photos in both directions from iPhone to Mac and back.
Gimp 2.1 loads and seems to work OK.
Polarr Photo Editor 5.10.21 loads and seems to work OK.
ExifStudio 2.5 loads and seems to work OK.
For video producers:
DaVinci Resolve 16 loads and runs. I'll be doing some video processing in the days to come to test it more fully.
DaVinci Resolve 17 loads and runs on my old MacBook Pro 2015, but I haven't done anything with it yet.
Shotcut 20.07.11 loads and seems to run.
Openshot 2.5.1 loads and seems to run.
Handbrake 1.3.3 loads and seems to run.
Take all this with a pinch of salt and a jar of caution as bugs often don't turn up until the program has been running a while, and they seem to hide in the most obscure places. I use On1 Photo RAW every day, but almost exclusively for asset management. And I'll be using DaVinci Resolve quite a bit. I'll report on anything I find.
If you are a music producer, you might like to know that the following AUs run well under Logic Pro 10.6.0:
Virtual Synths
KV331 Audio SynthMaster 2.9 and SynthMaster One
Lennar Digital Sylenth1
Native Instruments Kontakt 5
Native Instruments Massive
Sonic Academy ANA 2 and Kick 2
Spitfire Audio BBCSO Disover and LABS
Synapse Audio Dune and Dune 3
u-He Hive
Xfer Records Serum
Effects
iZotope Neutron 2 Advanced, Ozone 9 Elements, Ozone Imager 2, Vinyl
Valhalla VintageVerb, Supermassive
Edit
I thought Neutron 2 Advanced was working but must have got it confused with another AU. N2 Advanced won't install, nor will N2 Elements, nor version 1. Hopefully, iZotope will provide a fix.