At that count I would guess verification is the bottleneck, and most of those sessions run against tests that pass or fail without a human reading anything.
Yes, while the first customers pay for something the founder can deliver alone. Support load tends to be what strains a one-person company before the product does.
It works best when the product fixes a problem people in your replies already complain about in public. Those first users then arrive from a conversation rather than a pitch.
Half the sales coming from one homepage review suggests the localised listing did a lot of the converting. Had the App Store page been translated before the sspai piece ran?
A question that arrives with the options and a default already written out gets answered much faster than an open one, so the wait shrinks even when the reply time does not.
Debounce trips people up because it is one clearTimeout before a setTimeout, and nobody rehearses something that short. Did you rebuild it from scratch afterwards?