This can't be done without a change in RLV specifications (since, as you pointed out, those notifications would be directed to the initiator of the command, not to the "victim") *and* cooperation from scripts (i.e. it won't be a viewer-side only feature, since scripts using the RestrainedLove commands would have to pass them the UUID of the initiator: such a feature won't be available for users of existing scripts).
Only Marine can decide whether this kind of feature shall go into RLV or not, so I recommend you post your suggestion
here instead.