Spraying Primer

Rolling was a fab back in the day. May still be viable process
On complete panels if air is not available. It didn’t work well on spot work.

I've done it with ncp270 back in the day with no problems. Just did it to see how it worked. Other than some excessive texture it was not a problem. You can dust a bit of blending reducer over the top of it to assist with the texture. Eastwood makes a roll on primer for this purpose. I've never used it so no idea how it works.