It feels like a render time boolean, but that can already be done with booleans, unless you mean that when you define an object as clip_geo object it will clip everything, but I doubt it since only one layer is being affected in the skull example.
I think it’d be awesome, if it somehow worked more fool-proofly than the actual geometry boolean. I’ve found that neither the old boolean or the new exact boolean really work all the time for more complex .stl imports (usually exported from some production cad files). I often would like to do those animated boolean cuts, but have had to resort to other ways of showing a cut section of a product, just because I couldn’t get the animated one to work without spending ungodly amounts of time cleaning up / remodeling the model (usually there’s just no budget to do that sort of thing, have to be efficient…).
I have no idea how a render-time boolean works compared to the geometry one, though, so don’t know if it would even be possible to have a fool-proof render-time boolean