Comment by drdaeman

Well, they all seem to have issues with multi-line selection, as those get all messed up with decorations, panes and whatever noise is there. To best of my awareness, the best a TUI can do is to implement its own selection (so, alt-screen, mouse tracking, etc. - plenty of stuff to handle, including all the compatibility quirks) and use OSC 52 for clipboard operations, but that loses the native look-and-feel and terminal configuration.

(Technically, WezTerm's semantic zones should be the way to solve this for good - but that's WezTerm-only, I don't think any other terminal supports those.)

On the other hand, with GUIs this is not an issue at all. And YMMV, but for me copying snippets, bits of responses and commands is a very frequent operation for any coding agent, TUI, GUI or CLI.