خالد حسني (Khaled Hosny)

That is by nature of these symbols, check them in other math fonts (Computer Modern/Latin Modern, or Cambria for instance)

These fonts were not designed to handle combining marks, fixing this will require an overhaul of how combining marks handled. No need to open issues for individual problems.

We already have a single storey g glyph for ɡ that is used in IPA, if math users really prefer a single storey math g, we can switch to that...

Both Cambria Math and Computer Modern are in style too far away from Libertinus, however STIX is far closer to it so it is an appropriate comparison IMO. I don’t...

Yes.

I think the question is already answered; a pull request to add an optional alternate italic g for math is welcomed.

Omega and t are both italic, so I wouldn't expect italic correction to be applied. The omega glyphs might have too tight side bearings or even -ve right side bearing...

Note that I want to merge the sources, then decide at build time if we are generating the math or text font and subset away the unused glyphs.

Can you make a list and a visual diff between the two fonts so we can decide which is intentional and which should be normalized?

We want to keep the brackets, braces, vertical bar etc. from the text font, make the math version an alternate, and swap them based on the build target.