I was doing the same investigation myself recently.
All of the keyboards in question seem to be a little lower in quality than the factory keyboards we are used to [e.g. Leopold].
But the situation has improved, more choices and even a hotswap.
I was looking as how to get Kailh Sunset low-profile switches into a conventional keyboard layout. It seems I have to use an odd 75% layout of somewhat dubious quality, or solder Sunsets into one of the Amazon boards.
Reminds me of the situation that existed with Kailh BOX switches when they were newer. MK.com was selling Costar knock-off boards with BOX Whites, Browns, etc… as options. Those boards weren’t as good as Filcos, and there were user complaints and 3-star reviews like there are today with the Choc boards.