The most lubricating soaps are usually neutral. However, low ph somewhere in the process before the wax/sealants is going to result in a better looking car. But if no attendant prep than you might need a little high to help with bugs, then you benefit from low to help get the high residual off.
Some owners just like to keep it simple, and go all neutral. My istobal is a very thorough washer and if there is a unit on the market that could go all neutral that would be a good candidate. If you are prepping all cars all neutral is not a terrible plan. But then you become overly reliant on labor to make your customers happy.
I inject a low ph additive into my brush rinse water.
Coach, if you wanna try some neutral foamers from quest, try suds up, cherry foamer 3xc, or super suds 3xc, the latter two being hypers.