There is no reason to try any solution that you don't feel comfortable with - if the scratches are only visible in sunlight and you don't see them unless you're looking for them, the answer is to stop looking for them!
The only purpose of my suggestion was that something like a liquid soap wouldn't so much clean the scratches, because if they are scratches, they're not cleanable anyway, but to partially infill them so they're not so noticeable. If they are not scratches but markings of some sort, then ideally you'd want to know what the cause it, to better understand the way to clean them off, because they're going to need something more than just wiping with a cloth.
IPA is good stuff for cleaning off residues, but these don't look entirely like that. If this is the residue of something, then even IPA is likely going to need something like a very soft sponge as a wiping surface to give it some frictional action to work with.
Personally, I'd leave them alone unless they're a major irritant when using the system. One concern would be that if there has been something in your environment (small particulates in dust, for example, if you're close to something like building work, major roadways, or even smoke from wildfires and the like) then anything you might try could actually be unwittingly making it worse, not better, since the particulates could be already embedded in cleaning cloths and materials.