Lol.. So you mean to tell me that your FPR that is a 1:1 will work with say a 12:1 FMU or 7:1 SFMU?? Either I'm highly misinformed or it won't work because the point of a FMU is to increase fuel per every psi of boost. With that being said, unless you have something to tune with (MS or portfueler, suggesting you don't since you have a FMU/SFMU) then you have no way to correctly compensate fuel. Because with a 1:1 + 12:1 FMU, you have no purpose with the FMU because the regulator will regulate it to 1:1 and then you won't have enough pressure for said fuel that you need.

Also you can't just "replace" your stock FPR. Not with a 1:1 at least.. Good luck, let me know how it goes. So I firmly stick by my "you can't use a FPR with a FMU/SFMU".