Hmm I am not the most familiar with the implications of shouldRasterize on CALayer, but it seems like it could have quite a large impact and is not something we would want to naively turn on for every border/outline layer we make, especially if the issue we are seeing is rather specific (scaling transform on parent with custom border drawing on child).

I would assume that there is some fix to the logic in the border drawing we have that would let us fix this problem without having to set this value, which would be ideal. If you want to tackle this issue can you go down that avenue as a potential solution? The code would live in RCTBorderDrawing.m