Merging Down on a layer with Oil Strokes

I love the oil brushes. I use them constantly and love the depth and texture of the strokes. But sometimes I want to create paint overtop of those strokes. I can simply create a new layer above the oil layer ofcourse, but eventually I want to merge down and create a new master layer. But I cannot. Because suddenly the texture of strokes in underneath suddenly persist through, even though I'm merging down opaque pixels. I'm not merging down a layer set to a layer transfer mode, I'm simply merging down opaque pixels. And when I do, horrible result. When I flatten: horrible result. I understand Live Brushes are a unique beast but there has to be a way to maintain how layers have always worked.
Apologies because I have posted about it before and Sue has mentioned looking into it, but it's becoming a real hindernece and I can't imagine I'm alone in this. I love fresco but this is a big issue. Any thoughts?