This is really interesting. I have been annoyed for a long time on how ssh, the terminal emulator, tmux, and the shell don't know anything about each other. I also started writing a native terminal emulator (no electron, of course) to fix these problems. I kind of thought I'd do the slow burn over 4 or 5 years of using it myself (being a shell sadly means writing a programming language, and you don't make a good one…
Even at these times you got tons of GNU and BSD utilities.
And since Slackware days, the commercial Unix' days were numbered.