Snap to grid'ing geometrical shapes is easy, but what about fonts? How do I achieve the sharpest looking fonts? Should I use text baseline to grid intersection? Or for fonts snap to grid doesn't matter at all?
Are you having difficulties with creating a font yourself ("achieve the sharpest looking fonts"), or is it merely the aligning of some text with relation to an object? If I understand it correctly, your question is the latter one.
So then I would say your question becomes, how to change the position of the text w.r.t. the text baseline? Would changing the vertical shift of the characters help? You can do this either by selecting the character(s) and pressing Alt + ↑ or Alt + ↓, or change the vertical shift directly in the Font Toolbar.
While editable, text is treated as "a box" or as an object, so to say. This also includes kerning of the font and it usually adds some space around the font/text. To avoid that, convert the text into the path(s) and aligning/snapping would work just as it works with any other object. Bare in mind that conversion would disable editing of the text, so it`s not a bad idea to create a duplicate before conversion - in case you need to do some editing of the text later on.
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You'll notice that the text baseline handle is always at the base of the text, so that snapping to a grid intersection puts the text always on the horizontal grid line, in the same way as if you'd converted to path, and snapped node to grid -- so that the bottom of the text can be aligned to the horizontal grid line. Other parts of the text, besides the baseline, might not necessarily align to the grid, because of things like Maestral mentioned.
If you need everything aligned to pixels, you can use Extensions menu > Modify Path > Pixel Snap.