The Line6 POD UX1 needs drivers so it's probably not class compliant.
The Focusrite Scarlett Solo 2nd gen seems to be class compliant so it should work in theory:
This is untested and not officially supported, though the Scarlett range is class compliant and may work on this OS
Don't get misled by all the latency mumbo-jumbo on their site, any decent USB audio interface can do real-time audio with low latencies.
The Roland Rubix22 is class compliant too, so should work also in theory:
Low latency, class compliant drivers
The Steinberg UR22mkII has "iOS connectivity" which means it is class compliant and should work with Linux.
So only the Line6 is not an option. Personally I've had good experiences with Roland and Focusrite but I've heard and read some pretty positive experiences with the Steinberg products and Linux too. I guess it's a matter of comparing features, price and usability. Or if you have the possibility to test them you could add sound quality to that list.