you can lower it for dispensing, but you'll need to turn it back up to 30psi, or it will vent carbonation into the headspace to equalize the pressure to 10-15psi.
the other option is using about 25-30 feet of beer line, to balance the system.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10