I can’t easily get X on my system to test
This can't be true. If you are on Arch, this should be very easy to do. I've had a backup i3 session available on my system for years alongside sway. It should be as easy as installing an X based DE and then selecting that session from the display manager
I can't speak for the whole suite, but Excel sucks in the browser. The browser version do not have all the same features as desktop. I only use Office if I'm forced to and use LibreOffice or Latex otherwise