It's nice that the sweet spot in "It's Boxing Day" (from the original "Holiday Lemmings") is now more obvious. However, I think it has another instance where the top edge is deadly. (I just watched RTW's playthrough of it in Superlemmini again and it appears that the top edge was advantageous for him due to the differing mechanics.) I almost figured out a different solution but unfortunately it didn't quite work.
Sorry chrisleec728 I completely missed this thread :-[
Thank you very much for reporting this. I'll admit that I haven't played the Holiday Lemming packs so I'm unfamiliar with these top edge problems. If you find any more please let me know :) I'll even look at the levels myself and find other undesirable problems.