Taking a quick look at the dev's SubscribeStar page, I'm guessing that he posts his previous version here for public access after releasing the next update. 0.3.6 was released to his SS subscribers (min $5 level) on June 30, 2023; that's the same day 0.3.5 was released here. For some reason, the June date is listed as the game's release date on the OP; I've reported that as wrong, but the report was rejected for some reason.New version has been out for two months. Surprised nobody has linked it.
It's true, the dev currently only has 22 supporters on SubscribeStar (and has no Patreon link posted in the OP), and the releases are only available immediately to $5+ supporters, so there are a limited number of people out there who could leak the game.
Assuming the dev's plan is to release 0.3.6 publicly once 0.3.7 is complete, then it's likely to be a little while yet. As I believe has been previously noted, the dev lost his main computer during a storm back in July. His rendering rig made it through fine, but can't really be used for anything else while doing renders. In fact, the dev may need to rebuild parts of 0.3.6 before he can even start on 0.3.7. He currently expects to be able to replace the computer by the end of September; given a two-month gap between 0.3.5 and 0.3.6, it could easily be December before the next update is complete.