One approach is to work on the effect in the Layer panel instead of the Composition panel.
Ok. I double clicked on my layer to ender the Layer Panel.
I can access and alter my mask from this panel.
But I can't see any effects (like Bulge or Mesh Warp). Is there a way to access those from the Layers Panel?
There's a View menu at the bottom of the Layer panel. From it, you can choose what to view.
Yeah, I found that view, but even after I select Mesh Warp as my view, I still can't see or manipulate the effect (the mesh grid doesn't show up for me to manipulate). All I see is the un-warped version of the main image on this layer.
NOTE - if I check the render box next to the view selection, I see the distorted image, but still no visibility or access to the Mesh Warp grid.
Any idea what I'm doing wrong?
Oh, yeah. Oops. Sorry about that. I had spaced out on the fact that Mesh Warp is one of those effects with a custom UI that you can only see in the Composition panel.
OK, here's another approach. If you want to lock a layer in place just while you're working on it, add an expression to the Position property and just set the values for x and y to whatever numbers they already are. This prevents you from changing the position of the layer.
That sounds like a good solution. I'll give it a try.