The biggest problem I have with Tramp performance is much deeper, the need to open a new connection for every request - it makes integrating other modes with Tramp much more difficult than I would hope for (e.g. I tried to make kubernetes-mode work over tramp, and it mostly did, but each refresh had to reconnect, which would freeze the whole Emacs GUI for a second or so; thankfully kubel-mode has a more complete implementation that handles this gracefully).

I've had this in my config for a long time. Seems to make tramp work a lot better:

    ; use ssh instead of scpx mode for tramp
    ; this should work a lot better with ssh connection sharing
    (setq tramp-default-method "ssh")

This was problematic even with SSH multiplexing?

You still have this problem even with a control master setup with ssh?

I can't and don't blame tramp, per se. My internet has regular hiccups of being completely disconnected. Pretty sure that is not fixable. :(

Not by Emacs, but locally storing backups and autosaves means it only matters when you're actively reading or writing a file via Tramp.

Absolutely. It just sucks, as my build are so much faster on the remote machine. :)

That is, a lot of my remote editing is not just idle edits, but edit, run build, burn down compile output of tests and other items I'm working.

If I really want hell, I'll try and run lsp remotely.

None of this would matter, if I hadn't built up so much muscle memory from when I did have good internet and it did just transparently work.