Yea -8 is plenty big as long as there’s no bottle neck somewhere. In your log with the vacuum reference connected I see 7.3 psi of boost and 62.1 psi of fuel pressure. If your base FP is 58 and your reg is 1:1 you should have 65.3 psi so the reg is not bumping it up or you don’t have enough fuel pump. Maybe the MS is seeing this and trying to compensate.