YES. The abdominal exercises one can do while up there. I do those. I also jade roll my face while hanging and then onto the scalp massage. If we watch Star Trek 6, The Undiscovered Country ~ we are reminded that the culprits who transported aboard wore gravity boots of another sort as they went about their dastardly deeds.
I used to be able to do upside down squats in gravity boots. Completely different work out for the legs and core. I have a pair somewhere but haven’t used them in years. The dense foam rubber was finally starting to decay. Mine are the original model circa 79 or 80. It was a daily routine for me for years. Really helped decompress my spine. I fell asleep in them a few times. Not recommended.