I don’t think this is possible, the inspector is a debugging tool, with some extension functions for the user to tweak a number of things, but hiding objects seems to be counterproductive for such a use…
There are a few solutions, like removing the node from scene.rootNodes if you want to hide a mesh (root) from the inspector (example), or removing a material from scene.materials, but this isn’t really supported, it’s more of a hack than anything else (and it may generate bugs, I don’t know the impact of removing objects from scene.rootNodes / scene.materials…).