I think the problem is less how much DC is making and more that he seems to feel obligated to deliver a game that meets the expectations generated by such largess. Updates are getting larger and more varied, to the point where they could almost qualify as standalone VNs in their own right, but his team isn't built to produce them on the timescale that most people would expect a Patreon-supported adult game to meet.
If he wants to keep up this level of production that's fine, but he's going to have to compromise at some point and hire another artist even if they can't match his style perfectly. Heck, with all of the art revamps we're already getting contrasting styles in the game (see the last update, which had both old and new Jenny depending on the cutscene) and nobody seems to mind too much. It'd help with his same-face problem, too.