Some of the vehicles that come through the shop are wildly varying in finish texture.
The Ford mustangs are really terrible for whatever reason, and regardless of the polish, pad, or tool they just don't want to "pop". These Mustangs and s9me other vehicles also exhibit strange behavior with coatings too. Usually when I apply the coating and wipe it off, it's incredibly slick once applied, but some of these other paint systems still feel grabby and somewhat "rough" (even after ironx, clay, and machine polishing) after wipe off. Obviously you can still feel a difference between the coated and bare paint, it's just not as stark a contrast with those "tighter" finishes.
Now, I'm just guessing here but in my mind it could be from just having "larger pores" in the paint itself. The irregularity in the level of the surface isn't going to help with the gloss or the texture.
Outside of wet sanding (I wouldn't even dream of it on a factory clear), I would give a good coating a shot, especially one that likes to be layered, because that first coat can sink into the microscopic pores, essentially evening out the surface, and the second coat will sit on top of that - possibly. Remember this is all just theoretical scenarios running through my head.
If I was personally faced with that situation I'd do two coats of your coating of choice, use their topper and see how it goes.
My favorite coatings are Optimun Gloss Coat, CarPro Gliss, Lite, and UK 3.0. Cquartz UK 3.0 likes to be layered, and Cory Caruth even talks about my theoretical assessment (he actually confirmed it for me) I mentioned above in their instructional video on how to install UK.
You might also get away with a sealant or wax to do that, but they just don't create the same film build that a coating can. Plus, you get all the boosted performance characteristics of a coating. If you like messing around with pure finishing waxes and sealants (I'm looking at you Optimun Car Wax and Opti Seal) Optimun Gloss Coat (2 layers) might be the way to go, because they state that it's perfectly fine to do so, even if it's shed from the surface in about a week.
As far as polishing, most of the cars I do are finished with an orange LC HDO, or Yellow Buff and Shine, and 3D ONE or 3D AAT502. Rarely do I need a black HDO, or AAT502 even. Eventually I'll probably be moving to the HDO CCS line, not that it matters here.