I'll be gentle.
Your description sounds good. The NO.#1 object is to avoid all rises and bumps, especially those that run continuously. xt are high/low edges around smaller areas. Feathering around all edges, without scrapping raw paper and creating texture (fuzzies), is what makes it possible for a Good primer to cover and lay up a smooth surface.
When primer is sprayed instead of rolled, then Coverage does not equate to "Hiding". There are not 2 or 3 substantially heavier coats that tend to "float" over minor irregularies. Nope, your just going to get it "White". Then...as stated before, when the high gain-High Contrast paint goes up, and irregular rise or dip...smooth into Fuzzy.....even slick sanded Mud into plain Drywall.....
.......if those area are there, odds are against you not
seeing them after the 1st to 2nd coats of Finish paint goes on. And the finish coats are even less intended to "Fill" or "Hide", so 4-5 Dusters will only highlight such errors all the more.
This all leads to two (2) choices at this point.*
- If the area/s are adjudged smooth and with no tactile difference in smoothness and Feathered edges, your good to spray on diluted Primer as Duster Coats...3-4 will do. Great practice for what is to come as the same 3' sec pace w/75% row overlap used with Silver Fire applies to Primer coats as well.
- You apply a skim coat over / across the raw drywall areas, blending them 3" - 4" into the just sanded areas . That coat is "skimmed....that is scraped away until you almost see the Drywall. But not quite.. It's actually easier than trying to apply and level thicker coats. The object is to apply a like material across the entire area so that a final sanding assure a wholly equal and consistent texture.
...................then you do the Spray Prime / Spray SF thingee.*
: If you use Lightweight Drywall Compound it should be smooth and "Plastic-y"...not "Cake-y" or "Runny", and using a 8" Knife, just load the Knife with a 6" wide x 2" tall Ridge of Compound and pressing it firmly at a 10 degree angle against the wall...smooshing it out, proceed to sweep the area so that a very thin coat is applied. Repeat. Fill in your bare areas. Then sweep scrape the surface with light strokes of a clean Knife. , knowing that your leveling and thinning, not really trying to "remove". You don't overdo any area....scrape 2x and move on. Sanding will finish the job.