Soda blasting will cut into the mud also. If the paint is hard, which even the uncatalyzed coat will air dry, i would take advantage of the material & Block with long board with 150 thru 220 & reprime. In order to help the paint cure, open it up with the 150, then stick it outside for a couple weeks to expand & contract & vent off solvents(paint vents solvent up to a year). Then block it religiously, accurately from 150 to 220. Reprime all the areas where top coat is gone through with 3 rich coats. After primer kicks, cut it open with block & 320 & again let it sit out & vent, expand, contract. Then block it out to the desired finish grit. That depends on type of paint...if it's two stage with watetborne base coat, then everything will have to be @ least 1000(some watetborne base coats call for 2000) If the base coat is solvent borne, then 400 is as fine as You want to go. Same with a solvent base single stage.
I'd suggest You pm eldubb440 & get His take(in the body work/refinish game, there's a million ways to skin a cat & nobody does every step all the same). He is very practiced on current materials. He did hsorman's RR a couple years ago & Hawk is very Happy with Dub's work.