I have both headphones and speakers setups and each gives me different musical enjoyment. Really good headphone setup delivers very intimate, involving, and incisive listening. My tube preamp LTA Microzotl has an excellent headphone out, but I prefer using a dedicated headphone tube amp like McIntosh mha200. Open back headphones like Hifiman Susvara sounds out of head or speaker like presentation with a good headphone amp. It is f**king ridiculous how good it can sound, but you need a very best amp to drive susvara. I sold mine because I could not power it with my amp. I got Abyss Diana Phi which is not hard to drive, but it also has some what open speaker like presentation. I like it’s tunning and low frequency handling. When it rumbles it’s super fun in the ears. You mentioned focal. I listened to buch of them including clear mg. I found it had a bit bright signature which was fatiguing to listen. However, I think Stellia is a fantastic cans. Very elegant and sophisticated sounds, Imo. I might get nice used one in the future.
I am surprised that you are thinking about ditching JA perspectives. Those are fine speakers and I am thinking about getting the graphene version. JA speakers sound best with a good tube amp or class a ss amp, Imo. You have a good streamer, but I think you can use a more musical dac, I use holo may KTE DAC. Fantastic r2r dac which sounds very smooth, quite, and detailed. I can listen to it for hours.
I cannot listen to my systems without my Puritan psm156 power conditioner and various power cables with them. Stupid money but worth it for the top result.