I think the most annoying thing here is the decision to blanket ban other browsers. Why not just have a little drop-down bar at the top that says ‘You may encounter issues, we recommend browsing this site with Google Chrome’, instead of completely blocking access? The cynic in me suspects it’s linked to advertising.
If one changes the user agent in Firefox so that it announces itself as Chrome, most of these sites work just fine. Adobe Express is the last example I tried.
You should replace ‘You…’’ in your response with ‘From an ideal security standpoint one…’.
OP obviously does want to RDP to their machine, they stated as such. For most people, accessing a desktop-class machine from a mobile device isn’t a significant issue.
It’s this kind of gatekeeping that keeps newcomers away from Linux.