Re: GDI P-Rom Rifle Optic Mount
If you have a 20MOA Base on the HRT the PROM adds another 20MOA too it, so the S&B 5-25X can work with up to 45MOA of cant, so you should be fine and able to get 100% of the elevation out of the scope.
Worse case, consider replacing the base with a 0 MOA model and then moving forward only getting 0 MOA bases on your rifles you plan on swapping the scope with at the PROM. But an S&B 5-25X should work.