"Physical paint flecks" limit instead of physical strokes limit

With the new decrease-detail we have for paintings, this would be a great way of using less processing on physical paint. For example, a stroke with 30 flecks is presumably roughly 10x more taxing to process than a stroke with 3 flecks.

If that's right, we can have a lot more strokes wobbling about in a scene before we start to see performance problems. And with the stretch settings etc. they can look about the same.

But for now, the limit is based on the number of strokes in physical paintings, so we can't get more strokes even if we make it easier to process. If the physical paint limit was based on flecks (points) simulated rather than strokes, this could expand how much we can get out of physical paint quite a lot.

(It could be that even using just the "fleck density" setting reduces performance load on simulating a stroke, in which case that should affect the "physical strokes" limit also.)