I doubt he'll switch because this way he can milk more.Seems to be "when it's done". I've seen no specific reason put forward by the developer as to why this update is taking as long as it is, so I hope this update is going to be huge to compensate. It currently sits at 93% complete and it's been over 7 weeks since the last update. If this becomes a trend he should switch to a "per major update" payment model on Patreon.