I have ASF, and I haven’t been able to fond a way to enjoy them. Over boosted muddy bass, recessed lower mids, glaring shouty upper mids, no mid to upper treble. Even with EQ it still sounds wonky to me. If you want an all-BA KZ, I can wholeheartedly recommend the BA10. If the shape is an issue, maybe the AS10 would work (though I have never heard the AS10).
Some note that the ASX sounds much better after switching the stock narrow nozzle for a wide nozzle, but I have been unwilling to try that mod thus far.
Oh, and I really did want to like the ASF. I like the build, and though it’s large, it fits me fine.