Soundlab speakers: Castors or Tiptoes?

I recently got an older pair of thoroughly rebuilt A1s in excellent condition and have them set up in the basement. Even though some landscaping work 2 years ago resulted in no more water leakage into the room, I am still a bit uneasy to set the speakers, or anything else for that matter, directly on the floor.

For now, I have the A1s on amp stands with the speakers extending about 4" off the stands on the sides and rear ..... but I know this is not a good idea for a long-term solution. I like the idea of castors, providing they are locking, because of the ease to move them around. But somehow this just seems a less rigid coupling vs cones.

Any ideas or experiences would be greatly appreciated.

John