Hi. Donny,
I beleive the pa4x also loads soundfonts , which sounds very interesting.
Have a heap of them from my old One Man Band soft synth arranger days.
Hoping I kept them.

I did a couple of sounds on my pa800, but they used wav files, plus I created an sd2 drum kit to go with one of my sd1 style conversions. Worked quite well.
I have tried sampling, even had some sort of software that did it automatically, but you could spend so much time on it, not enough hours in the day. Haha

For my pa4x , I may just try and find or redo my brush swishes,

Do some more sd live drum kits if I decide to try and convert some more Ketron styles,

Just for the heck of it, might see how well a soundfont works.. Really only worthwhile if I can't find an onboard sound to suit my needs. My curiosity may get the better of me. Haha

My pa800 user styles, I always shared over at the Korg forum, so I tended to stay away from anything to do with someone having to load samples and sounds.
It could have interfered with their own , if they had samples loaded.

Certainly is amazing what can be done on the korgs.