Sorry, I haven't tried clear coat over cellulose. I use wet and dry, 800 to smooth out any runs or drips, then all the way from 1000 to 2500 grit. Farecla G3 cutting compound takes out any swirls, then a final polish with Autoglym Super Resin leaves it shiny. Works for me
Here are my efforts at amateur spraying, achieved with a bit of internet research, some advice from a pro, a cheap compressor, Jawel cellulose paint and a £150 spraygun -
What are you spraying that needs a modern look to the finish?