I am late to comment but I really can't thank Rebecah enough for her input on this tricky project & I'm pleased to see that the 'other' balloon is now available because from the same beginning they've turned out very differently. I am certain that people will appreciate the choice (certainly I suspect my design may be a bit too flowery for a lot of people's tastes and the I couldn't sort out the slot problem to make mine work seamlessly without one of the later EP's!).
Custom animations are a pest, having winced and wailed over the final revision that went into ours, I can see all why it's so limited using Milkshape *but* that doesn't give anyone any excuse to complain imo. Not that it stops anyone, but then being the charitable soul that I am, I'd give them a totally free slap around the head, possibly accompanied by a lecture, depending on how generous I was feeling that day