I'm surprised this issue with your SOP has not come up for discussion before at FR.
As many here have stated, it is probably safer at 50ft to continue the landing unless you clearly do not have a visual reference (Cat3a). By including a mandatory go-around at 50ft DH in the event of pilot incapacitation, this would appear to be unnecessarily loading the remaining pilot (who may be a very inexperienced F/O in your position) at a critical moment.
What do your colleagues think of this particular SOP? Surely you must have discussed it amongst yourselves at some point?