I'd honestly love it if non-standard comps with 1 healer just randomly gave a DPS a status effect designating them as the target for healer mechanics. I mean, why force PF groups adhere to the standard comp when the healer feels confident and more engaged solo healing the instance? Even if you go by the logic that the healer must be some elite of the elite to pull it off, what's the harm in rewarding them and the group with faster clears for their expert healing? I see no reason to arbitrarily force the standard composition.