Yes, it would have helped. I guess it depends on if you encounter the stopper problem or slam problem more often. Although, as people have said above, you can use a western cue and then later in the auction show you have a slam try. Had partner used a western cue, I would have responded 4♥ as I want to be in hearts even with spades stopped and don't need a good fit for that to be a good contract. With a more notrumpy hand but the same extra values I would bid 3NT. With minimum values 2NT or 3♥. So partner should get all the information she needs.