100% this. Per-topic RSS feeds solves this perfectly.

Nah an RSS feed has the ability to contain n feed items. This proposed new protocol would have a maximum of 1 item. The closed contract (1 notification only, ever) makes sure that it doesn't become yet another avenue for producers to push content that you didn't ask for.

	▲	akoboldfrying 7 days ago \| parent [-]
		"RSS but for just 1 item" and "A brand new protocol that is functionally equivalent to RSS for just 1 item" are both just contracts. What makes you think that the latter is more enforceable?