If the headphone upgrade in sound isn’t enough, then buying further would be worse.

You have enough mW to drive the headphone already. You could try a discrete amp like Schiit Asgard 3. It should widen the sound stage a bit and provide warmer/thicker sound.

Not sure if you’d think spending another $300 is worth it though. 😂

I’d suggest give it a few days. When you’ve adjusted your M50X for so long.

If anything, I think you’d rather like V shape planar. Same clarity and separation but with emphasis on bass. M1060C/1070C should do the trick for much cheaper.