Isn't it a good time to finally fix this very old bug?
Since the early typesetting programs, sidebearings (which are nothing more than a way to define default spacing between
letters) have been used to align text.
For 30 years now, all text has been misaligned with respect to the optical edge of the glyph. The most interesting thing is that in most fonts this offset is known and corresponds to the margins of the letter 'H':
If corrected by the 'H' sidebearing, text alignment is magically fixed:
Some time ago, I discussed this problem (and solution) with Ilya Zherikov, who then created a plugin for Figma that implements optically correct text alignment: https://www.figma.com/community/plugin/1007645801320386272
Of course, the 'H' "hack" is only a very simplified way to solve this, there should be a way to properly define "default" optically-correct edge for all glyphs of the font and a way to specify it for individual glyphs.
There are OT features registered for this ("lfbd" and "rtbd"), but 1) nobody puts them into any font; 2) there are too many fonts already without these features, which takes us back to the "H hack".
What do you think?