Dev said some time ago that game code turned into a mess and he was planning to finish game earlier than originally planned, I think after that point updates became slower, dev's communication became rarer. At some point he may say fuck it and may never return. So far he returned from his long absences, so still there's a chance he may come back with an update. I believe not a scammer dev, more likely a frustrated one, he paused patreon payments several times (don't know if it's paused currently).
TLDR: I think you shouldn't join his patreon currently. If he delivers an update then for sure become a patron until the next disapperance.