I am on Rebug 4.21 Rex with III(downloading SA), However I am puttin it on OFW and the I data transfer and simply activate the second CFW online. Rebug will spoof to 4.31 with the toolbox.
I also took a run at modding it, well the param.sfo anyway. I tried enabling the ps remote play and guess what happened? Changing that around gave a black screen, even when I put the original back. Have to do another transfer when SA is done anyway, but weird.