You could give it a top coat of black primer or sealer. Although imo that makes it harder to see any light coverage areas.
I’d shoot the base over the high build anyway as long as it’s a good 2k urethane primer. Although I recognize the benefits of sealer.
Regardless, you do want to do the inside of the cab and all the jamming and misc areas first, unless you’re a pro. I’m not and I could barely handle doing everything from the upper trim line at the same time. (Which I did for color consistency, although I can see no differences in the other areas I painted the light color separately. Nor can I see any differences in the dark blue bed and cab which I did separately.
The challenge is what to jam out and how to mask it or cover it later. As you don’t want to be spraying new base on shiny hard clear. For obvious reasons.