I have a friend that lubes his sabots with bore butter and gets good accuracy with his Knight.
He shoots, runs a "spit-patch" down & back followed by a dry patch, then drops the powder and rams a sabot coated with bore butter. Groups are about the same as with un-lubed sabots, but loading is a lot easier.
Come to think of it, I use lubed conicals, and lubed patches on round ball loads, what would be the difference?