Don't use it on battery FAENIL so I'll leave that to someone else.
After spending hours with the MSI curve editor, I think I've found the optimum curve for the 2070RTX. Memory is set to +300MHz. This elimates all power limit throttling in games but still gets the odd minor flicker of it during 3DMark. 3DMark isn't a realistic load so I'm not concerened by it.
Likewise, for reference my laptop crashes at -150mv so i've kept it at -130mv. But potentially increasing the undervolt on the cores could be a good idea. For now my laptop is running very cool since underbolting. I've played League and it runs at roughly 60-65 degrees and then Borderlands 2 between 70-75 maxed out. Using a cooling pad too, but still very reasonable temperatures as before undervolting I was hitting high 80s during Borderlands.