Matt, you really need to know what timing the combo (cylinder head, piston, plug location, compression, etc) wants NA before you start to build a map for boost. For example, my 489 BBC twin turbo wanted 41 degrees NA on pump gas. So on 10 psi I run it at 30 degrees. But on a turbo LS or gen3 that’s much more efficient, they want 28-29 degrees NA so running them at 19-20 degrees on boost isn’t unreasonable. Make sense? It’s very hard to throw out some arbitrary numbers that are “right” or “wrong” because it’s very combo dependent. Knowing where the engine makes best power NA really helps to determine a starting point for boost timing. It will definitely want less at peak torque and more at peak HP.