Well what I do is use the cab on stage for me to hear myself, via the Output 2 to the Matrix and separately I send XLR's L&R (with cab sim) via Output 1 to the desk which goes to the monitors and FOH.
The idea being that everyone is hearing the FRFR signal, but I'm hearing the 2x12 cab.
However, I've found that the cab alone fulfils the job on it's own in smaller venues. It's pretty loud. You may think it sounds 'thin' on its own but in the context of a live mix, that's exactly what you need in order to cut through properly. Give your speakers time to break in if they're new. It will take a while.