It will be accentuated by your color coats, considerably more peel than you got there now and the nap of the roller your using can make it even worse, Black is actually the absence of color, and very difficult to pull off as flat and perfect, too much orangepeel and you may run into sticker/art adhesion problems.... I would sand it flat without burning through, and start building up your desired texture again using the same nap roller you used for the primer, and the first 3 coat system first described. Don't stress though, if it doesn't turn out as you wish, We can color sand and do another coat after it dries, (if you still have enough paint, and easiest in the 12-24 hour window after your first paintjob).... Trick: on your first coat don't be all about coverage, put it on light and even, there should be some bald spots, but coat #2, complete wet coat covers that and #3, complete wet coat (slightly thinned) melts it all together.
Just wanted to update you on where I am at now. I spent a while dealing with the primer coats.. had issues with primer wearing off the face of the edges while sanding but got to the point where I got it smooth to the touch despite those spots and started the paint job now.
The primer spots didn't seem to cause too much issue with the paint.
My first coat didn't go very well LOL. I used way too much paint on the foam roller and ended up with a lot of paint runs and some roller marks also. I also had the issue of dust landing all over the wet paint while drying.. not just dust but hairs and little bugs too. My garage I guess is pretty dusty probably from working with the MDF and sanding so much before this.
Anyway, I decided because of these imperfections, I would do a light sanding on everything to try to knock off the dust and stuff.. but also had to try to sand down each of the paint runs which resulted in several spots that were sanded to primer while doing that.
I was not sure if I should repaint only those spots before doing my 2nd coat... so I just ended up doing my 2nd coat tonight and it went a lot better technique wise.
No runs that I can tell so far but still have the issue with dust and hair landing on everything. Not sure but I may see some roller lines also on the door atleast but the sides look ok.
New problem with the 2nd coat, the spots that were sanded exposing primer of course are thinner and I can see a little of the primer showing through those spots. I guess essentially what I have done was put a first coat on those spots and a 2nd coat everywhere else.
So I am wondering now should I paint only those spots again before doing a final overall 3rd coat, do a 3rd unthinned coat to get better coverage followed by a 4th thinned coat, or just to the 3rd thinned coat and everything will be fine?
The other issue is I didn't realize the temperature was going to drop tonight to around 43F so I'm not sure how that will effect the paint drying and how it will look but I am going to let it sit for 48 hours instead of 24 because of this.