if you look further down the list in the SceneTexture node you’ll see PostProcess0, PostProcess1, etc. I can’t confirm if that will make a difference or not but I can’t see why it wouldn’t work. SceneColor is just the cumulative colour passes before post processes are applied. Up to that point in the material you’re just gathering the pixels you need to apply them to custom depth.
The menu layout was changed slightly it the latest versions, so that’s why you’re seeing a different label, but the one you’re seeing the proper one. An easy way to tell is by typing “custom” in the search box at the top of the property grid. It will filter out everything but the matching options.
I’ll give this video tutorial a shot today to see what the problem is.