Magic Mask - Flaky in Fusion and Color Oage

I’ve used Magic Mask in Fusion (v18) and it has a multitude of issues, one being that it takes roughly 5x longer to “render” than the Color Page. It also is not consistent even on a clip made from a photo whereby the first frame is frozen (Time Speed node I think). Artifacts pop up while playing the clip. I find that bizarre considering that the clip is of a still image. On the positive side, Magic Mask only renders one time though it takes a long time.

Ye on the Color Page, the behavior is the opposite. It “renders” quicker but often needs to re-render for some reason. So, I’ll scrub through to view the clip only to find that MM on renders on the ref frame. It’s annoying, time consuming, and unpredictable. Will failed renders render properly when creating output?

I’ve heard that v19 greatly improves MM in Fusion.