Use nova for years, but never found an of the features beneficial. I've been using One UI since moving to the s24u and I have noticed no real difference in functionality.
folders, grid size, customising badge notifications, dock size, multiple docks, multiple tab pages in app drawer, hide icons in app drawer, drawer groups, etc. those are some of the things i like in nova :)
I don't know what's required for KLWP support in a launcher, but KLWP is a live wallpaper with touch interaction. Don't know if stock support that on my phone. But some cool setup like media player functionality, time and such, in the font and size I want. And some other disguised shortcuts.
But for me in actual Nova, it being able to style app icons individually, swipe actions on app icons, and the dock at the bottom being able to slide to have more apps. And pretty standard now, but swipe up for app drawer and down for notifications. It works especially well with OnePlus gestures that I'm still holding on to.