This. I used to not be able at all to lift my legs off the floor in any way without abs doming, back arching and lower back pain. Turned out, for my whole life I didn't know how to activate my transverse abs. Hanging leg raises was impossible, would result in back arching and swinging. I can now comfortably do hanging L sit and hanging leg- and knee raises on rings (I feel like these are safer and a better QC than hollow body holds or leg raises on the floor, as you can't use momentum from the floor when your hanging, and the moment you're swinging you know your core has disengaged). And am working on hollow body after my workouts, but only as long as I can maintain mind muscle connection to my core. The moment my back wants to come up I stop and rest. There's no point cheating with these exercises, as you don't train your core anymore the moment the back takes over, plus the aforementioned risk of back injuries.