Might want to check out different filler primers, and dropping the layer height will help some when used in combination with that. Mr Surfacer has multiple thicknesses, and there’s other options and manufacturers too.

That was Christian Bale, in Equilibrium

The previous case was a hoax, in the end.

Regarding the nozzles, have you checked out MicroSwiss? They make a drop-in replacement hotend that enables the use of their flowtech nozzles, which include CHT, CM2, and Diamondback options.