I don't like this combiner approach with a 4 minute delay. It seems toOTOH if you want immediacy you can enable it as a web/app notification. That's even faster than prompt email delivery.
Of course, that won't help you (yet) when using the mobile app.
I was concerned with the first-out delay time introduced by the combiner, but now I think I may be fine with it, given that push notifications are still immediate.