Sounds like a good plan. However, don't tell yourself, "Oh it's only primer, I don't need to be too careful laying it down."

That's what I did and wound up with a lot of drips and rough areas and roller marks. These areas take a week or more to dry all the way through (because the paint is so thick) so most of them didn't get sanded smooth.

As a result, not only do they show through my main coat, but I also kept sanding through to them while wet sanding later coats, and they really stuck out because my primer is a darker color. And once that happens, you have to try to build the paint back up to the same level as the surrounding paint and let it dry and that's an f'in nightmare.

So be really careful to avoid drips, roller marks and rough areas, and when it's dry, wet sand your primer as absolutely flat as you can get it, because believe me, any rough areas will definitely show through your main coat and cause big headaches. .