Golly, do I have mixed feelings about this. Both as a developer of TUI programs - in which determining the width of a widget is already a complex operation (same as in GUIs) - but also as a user who is already occasionally frustrated by double-width Unicode characters in terminals, which frequently don’t handle navigating such text well or correctly. I can only imagine the chaos this will introduce into text selection, text editors, and readline.

OTOH, very cool. Unicode combining characters have great, mostly unrealized, potential, in no small part to consequential sizing issues.

OTOOH, the world of computing is now a little more complex. Is the added complexity necessary, or just feature creep?