Pics as promised, taken under a t5 5K HO light fixture
good pic's. Yup they're just as I thought, more like tiny pits or etchings.. It's probably some kind of sap etching or caused by sand particles.
Where do you live (don't need address, i.e. upstate NY, or Nevada...) This will tell a lot about environment and conditions. For example, here in the North East, we have a ton of Pine and Maple trees, thus sap... plus a lot of sand from sanders in the winter. All that sand spray in heavy traffic will cause that too.
It's common to see like this S550 I worked on. Under the Husky LED Lights, there was no denying it.
Even after full paint correction, there were still tiny pits in the paint:
Perhaps too far down for the 3000 & Compounding you've done.
Take some paint measurements... The only thing left to try is 1500 grit.... depends on how much clear and if you're willing to risk it.
You should get an opinion from a body shop before going to any deeper lengths such as 1500 grit.
These things can become like puzzles or problems that our brains won't let go of and will keep us up nights until we know how to fix them. That's why we're detailers. If you get to the bottom of it, please update the thread. We would like to know the outcome.