The following projects run much more slowly after the latest update: https://scratch.mit.edu/projects/55095796/ It also seems that the number of triangles per second reported is incorrect (I've tested this and it seems that the timer doesn't update during non-refresh custom blocks).
In addition, it seems that there are random pen dots which shouldn't be visible.

My browser / operating system: Windows NT 10.0, Chrome 73.0.3683.103, No Flash version detected