When you edit style ( volume change, tone etc..) you have the ability to rewrite that particular style. Korg is the only one that I know of that let's you overwrite all the factory presets. This could be tricky if you screw it up, but overall - it's great to be able to customize the unit to your specs.

If you change a STS, rewrite it into that style with "save style prefs".
Got it?

Enjoy!