My experience as an old painter is that the longer you wait to polish new paint the more permanent your results will be.
Here's the reason... Paint continues to shrink during the curing/hardening process. This shrinkage results in a surface texture change and that surface texture change results in lower gloss.
Paint application and thickness play into how long the curing/hardening process drags out and how much shrinkage occurs, but it does occur to some degree regardless of application/thickness.
So, the further down the road to full cure/hardness of the paint you are when you do your polishing the more permanent your results will be.
This does not mean that you can't polish fresh paint. Most paint can be polished as soon as the next day but in doing so, don't expect it to retain that "polished" look a month or two or three later. It will dull out to some extent. When that occurs just simply repeat your polishing process.
When I did custom paint jobs my preference for sanding and polishing was a minimum of 90 days out.