Topmost layer is intentionally ignored by "Add missing masks", but omitting it results in a non-functional FX layer

[hai-vr]

Study a case where despite having Write Defaults On in a FX sublayer, it needed a mask for Gesture transforms to function

[hai-vr]

It appears that the layer that caused the issue it was a toggle on the topmost layer. The topmost layer is ignored by the Add missing masks process, because of past unverified assumptions, topmost layer might need to be the sum of all masks, and might be modified by VRChat.

However, it appears that adding a mask might be necessary if the topmost layer mandates it