I would say at least wait until the levels have been finalised. Doing them for LPII Bonus pack or Covox is probably fine. But yeah, there's not an overly huge interest in challenges, and 95% of gimmick attempts are either extremely easy or obviously impossible, though there is the odd interesting one, so I don't think a topic is worth it.
It should also be noted that there's a slight difference between this topic and the One Skill gimmick (even though said gimmick was quite obviously inspired by this topic); if you were to try to select the same lemming twice in this challenge, you'd end up with an attempt that fails the challenge (or if you used ccexplore's patched version, you wouldn't be able to select it a second time), whereas the gimmick would ignore the already-selected lemming and assign the skill to the next lemming in the priority order.