[vorporeal]

Good call-out - definitely a bit of a simplification there. We account for this in our terminal grid by allocating an empty cell following any double-width glyphs (e.g.: emoji and wide chars, as you mentioned).

Tried out your example in Warp, and the alignment is as you described: https://i.ibb.co/Jcwcnwn/image.png

Core Text supports rasterizing at sub-pixel offsets (though some configuration of the graphics context is necessary to do so properly) by applying a transformation to the graphics context before the rasterization call. I'll definitely have to figure out the FreeType angle when we start working on Linux support; if I uncover anything (and remember this comment thread), I'll report back with my findings. :)