It's pretty common. GNOME's terminal does, as does Kconsole for KDE, and so on. I've got Gnome terminal bumped up to 100,000 lines.

There are definitely some that don't, or don't make it configurable, which for me just gives me pretty strong incentive not to use them.

Yeah, I thought this was a feature of the shell, not of the terminal

It is not

tmux FTW