I've played a fair bit with the roundballs.
I've used only Unique so far, but they work pretty well out to about 100 yards in my formulation. I developed these with 13 gr. Unique for my .45-70 BC, because with the long barrel, some of the reduced level loads I tried, just dropped out the end of the barrel barely. I started at 6 gr. and the ball was less than 4" from the muzzle. I bumped up to 8 and it went about 25 yards dropping madly. At 10 gr. I was on target at 25 yards, so I have some of those for really mild close-ups.
I honestly haven't used any lube, but was considering dipping the tips in Lee Liquid Alox. I used my expansion die to seat the balls consistently just past 1/2 way and then FCD'd it very lightly. These pictured loads have been bumping around in my hunting bag and range bags for probably 10 range trips and none of the balls has shifted or been pushed in.
Good luck finding your low-load.
***edit***
Just remember to decap without sizing.
The first set I did I sized without thinking and they were really inconsistent and kept shearing lead off the balls even after expansion. These are .457 RB.