I have always done a single coat of prime - usually I go with Benjamin
Moore's Fresh Start then two coats of paint, and that worked well.

Now I need to paint some exterior fascia, and soffit ceiling on the exterior
eave areas. The fascia is high up so I have to paint on a ladder, and the
soffit ceiling is T4 T&G so I have to use a roller from the ground and then
get up there with a paint brush to make sure I get everything in the
grooves. It's 90 degrees out in Miami FL and this is pretty brutal.

So...I am thinking of some shortcuts.

The soffit ceiling is T4 T&G boards, the fascia is 4 cascading layers of 1x6
PT.

Can I do two coats total instead of one? Say I tint the white primer to the
top coat color, then apply top coat, is that ok? or better bite the bullet
and do it right?

Thanks,

MC