I set and forget (set the pressure to 8-9 psi and leave it alone for 2 weeks). No issues that way with adding more kegs. However, I don't see why disconnecting your carbed keg while setting your second to 30 wouldn't work.
Cheers
I made this in October and finally transferred it to the keg tonight. Even though it isn't carbonated it is the best brew I have made to date!!! awesome recipe...much appreciated!!