You're welcome. I'm always happy, when someone actually takes up suggestions (and I always have alot of suggestions to many games *lol*).
Yes, of course I will enjoy it, because it's simply a great puzzle game and I also enjoyed the first levelpack, that came out and have it played through. Maybe, when you have the undo-function ready, this feature could be included in the already released versions of the game afterwards? It's very often the case, here on the website, that a v1.1, v1.2, v1.3 etc, of the same game is released. You might want to think about it.?