not want to judge any of them "Influenza"-guys on YT...I do watch them as well from times...
so just my 2ct on my Rotor Uno setup.

running it on my Yoeleo gravel Altera...1x13
set it up with 13sp AXS 10-46 Force cassette, flattop chain
(there is one thing you do need: a custom derailleur hangar)

and it just works perfect...so I cannot imagine why they were not able to install a clean shifting 11-46.

anyhow...thats just my experience
(yes, calipers are somewhere near an Ultegra brake...)

cheers

I was thinking about using the same setup for my new bike. Care to explain what the custom derailleur hangar was needed for?