#1 most based way to paywall stuff is to lock the more incremental, smaller, buggier, less-polished updates behind the paywall, then only do public releases when you decide the game is stable and polished and ready for another update, having enough content to justify cleaning everything up. Downside to this method is that you need enough people to pay for access so they can help debug and playtest the game.
I remember a dev once that did it the other way around, the indev updates were the "demo", but the paid releases were the polished ones, and if one of the public updates had a game-breaking bug in it that makes the game literally unplayable, then too bad, gotta wait for the next public release, or winkwinknudgenudge buy it.