Yes, MLok is a defined standard that is compatible regardless of who buys it or builds it.
Personally, I find the plastic-bolted-on-a-frame looks of the XRS, Bravo, older AIs, etc. insanely ugly and I wouldn’t want one in my safe. That’s not to say they’re bad chassis systems, I just don’t want to look at them. To that end, I’d go with a Woox over an XRS.
I’d go for an ACC, ESS, or ARC Xylo for a more functional chassis, though. I don’t like that you need to get a bottom metal to work with the Woox chassis; that adds additional things that can go wrong with getting the system to work together, and the resulting potential for more fitment work.