You can buy the game in Itch and you'll have access to all future versions of the game. I spent $10 on it however long ago and I've gotten to play every version that they've released, including the weird "prequel" game that they made that was on a different engine.
That said I certainly don't encourage anyone to drop money on a project that has had such a shaky development if they aren't certain that they want to support it. Honestly most H games seem to have very little development go into them despite all of the money that they seemingly rake in. Fap Nights for instance makes insane money from their Patreon (assuming the member count is accurate) yet they barely are able to push out more than like 1 maybe 2 updates a year, and when they do finally push an update they end up breaking half of their game.
