You are 100% correct - aside from Canaan (up to the A10xx) all of them are in violation of GPL. As I said in the other thread
In my book he rightly refuses to support folks who do not care about copyright and usage licenses. He cannot reasonably block equipment from Bitmain, MicroBT and a few others that started the chain of violation but he can keep the far smaller number of folks from using 3rd party mods of it on his pool.
There is of course a point where it is useless to rail against the storm. If he wants to run a pool then accepting How Things Are to use the major brands
as-shipped comes with the territory. Supporting a handful of miners that further violate license does not.