For me Tumbleweed is robust and stable like a rock and I don't see the need of a slower version but I understand some users were leaved "systemless" some times and it was an uncomfortable situation.
Any way I don't like any of the proposed names so I want to suggest a couple of them. "Tumbleweed step" because a step behind from tumbleweed, or Tumbleweed trust or trusty, for obvious reasons.
Regards.