bmap-fonts with custom per-character width ...unfortunately, every character's width needs to be hardcoded, but after that it works perfectly.
edit: Seems like generating the text is reeaally slow. This only needs to be done when the text changes but in the example this just barely works within a single frame (at 60 fps). So if there's a lot of changing text, it could cause fps drops
=> damn bmap_blitpart, looks like I'll have to write a shader for that.