I typically hit my new kegs with 25-30 psi for 48 hours, then purge and serve at 10-12 psi...
Based on your process thus far, I think I'd let it sit overnight at 25 psi...then tomorrow, purge and reset the regulator to 12 or so...
Primary: Sour Brown, RIP Stout
Kegged: Pumpkin Stout
Future Brews: a gluten-free beer for my mother-in-law, barleywine