> The biggest problem is when a glyph is reused for multiple things, as in that case the graphic has to pick one of them or stay generic.

Solution: https://github.com/mifki/df-twbt

This is included in various content packs, so setting this up manually is optional.

> The game doesn't actually use ascii output, it renders the text (windows terminals would probably be too slow)

Linux and OS X terminals are fast enough. The init.txt setting [PRINT_MODE:TEXT] switches the renderer to ncurses.