Decades ago I made my prompt simply end with a
newline, which perfectly
and cleanly solves the problem of making it easy to copy and paste a
whole line
I never considered setting a copy/paste-friendly prompt but I strongly
dislike prompts taking up a line. Admittedly it's nice to have some room
for extra information but then you'll want a clear line above it too for
visual structure and that's all just too much clutter for me.