In my very humble and unprofessional few tests with those two, I think they are quite safe in many scenes. Scrambling Distance in low values makes things really weird, but at high sample rates it magically converges to stable images. It would be nice to have builds that include those two features, but I also understand arguments from developers.
By the way, is not the AO bounces trick reducing much more render time compared to Scrambling Distance?
https://blenderartists.org/t/brechts-easter-egg-surprise-modernizing-shading-and-rendering/505373/16479
https://blenderartists.org/t/brechts-easter-egg-surprise-modernizing-shading-and-rendering/505373/16488