My initial thinking was that Aberdeen, Washington could support three of these projects. Aberdeen was about 17,000 people. I think you could divide total population of a city by 6000 to get a very quick and dirty estimate of potential demand for two towers projects.
I would then cut that in half for an estimate of how many to START "immediately." Because it's an unproven model etc., so you should be conservative until there is more real world data available.
This quick and dirty estimate will not work for all communities.
If you have a very small town with a mostly tourism based economy such that it has a lot of hotels and eateries, the local permanent population divided by 6000 likely will give you a stupidly low ball figure.
You would need to get data on repeat visitors to estimate potential demand for vacation homes plus data on local homeless people and other means to infer demand for small, affordable primary residences.
You might also need to consider impact on the hotel industry. Building several quickly and filling all the units only to find you've killed a hotel or two might well get you sued. Ticking off locals to the point of having laws changed because of it can be a significant business problem (a la AirBnB seeing its business model black balled in some cities).
There is a lot of research behind my figures but this is still hypothetical. IF projects based on the info here ever get built, then it might be possible to get real world data saying "Oh, no, demand is x percentage lower than she thought." or perhaps "Wow, everyone LOVES them and we can build x percentage more!" or even "Works great in towns with strong tourism, not so great elsewhere (unless there's a big university and then only with X adaptations)."
I've been studying this problem space for more than two decades and have firsthand experience with living in small rental units that weren't adequate to my needs (aka "poverty housing"). But the reality is you can't know if it works, much less how well, until you build it and see if it actually flies.