Well, I managed to knock out 1 ball, drop it to the floor twice and find it both times. It popped back in.
I wiped down 1 rail and greased and ran each block back and forth a bunch of times. There is still the feel of the balls moving, but the detent feeling is now very minor.
After watching more videos, I don't think they're as smooth as the original HIWIN. Most of the videos were the small setups 12, maybe 15s they were whizzing back and forth with a finger.
I can pick up the rail vertically with all 4 blocks on the 1 rail by one of the blocks. So it does take a bit of force to get them moving.
Debating ordering my Z set from another source for comparison. I've seen BST mentioned and did order a ballscrew set from them. Also auto-overstock. Thoughts?