Belgium/check valve question

So I just a kegged a strong Belgium (delirium tremens clone). I know belgiums should be car bed a bit higher, so I forced carbbed at 20 psi. I have a 3 keg system with check valves on each keg. Since I carbed my Belgium to 20 and the rest to 12 psi will I be ok lowering the regulator to 12 to satisfy needs of rest of kegs?

To recap I h ave 1 keg at 20 psi while i have 2 other kegs at 12 psi all off same regulator. Will check valves work with this? Btw I will periodically close other two kegs off and put 20 psi into Belgium. Then reset to 12 psi.

wow 20 psi sounds like a LOT of carbonation, almost soda level...

As for the regulator, are you saying its a single regulator with a manifold, and each gas line after the manifold has its own separate check valve?