I had a "professional" awlgrip job go bad when a boat yard used a rotary sander. When they painted, the surface looked like a fun house mirror, with periodicity of ripples about the side of the sander disk.
The correction for this involved using a product called "high build" and long boarding the boat (sanding with sand paper on 6 foot long boards) to get the surface fair. To insure it was fair they used a blue dye that would show the low spots when they long boarded. They kept applying high build and long boarding until it was even. The end result was a mirror finish with very little distortion. Watching this process, it was hard work and time consuming for even a big crew.
You may not be as picky as we were (having gone from a faired topsides rippled topsides did not make us happy) so this may not apply, and this was done "professionally" so your results might be better
. We are not experts, just victims.