I think he was referring to a listener you could send to the blockchain that would let you not replay the entire blockchain and analyze event by event (which is what the yo notification framework does) but to tell the blockchain "only send events if they match this criterion". But as I think it's not possible, I think your solution is the best one out there.
Yo not in JS but it's awesome RPC API seems awesome, so I'll try to integrate it to my code.