I seem to have stumbled onto this issue as well, playing around with the demo project from a water tutorial:
https://playcanvas.com/project/533435/overview/toon-water--tuts-tutorial
The project uses the depth map to generate a foam line around objects in the water, but that doesn’t work in the editor with the current version of PlayCanvas, only in the published project.
I tried forking the project, adding Will’s RenderDepth script to the scene, but to no avail. Any ideas what else is missing to get the foam line to work again? It appears that accessing the depth map has become a real hazzle – do we have any updated documentation that explains how this is supposed to work?