A little bench racing

Would lowering tire pressure on a street tire have a positive effect on launch? Say from 35psi down to 25-30 or is that more of a drag radial/slick thing?
No, the same applies to a street tire, or even off-road. What is your current psi in the rear tires?

Pump the front tires up to their max pressure, and play with 26-28 psi in the rear. If you are really at 35, I’d imagine a drastic improvement will be noticed.