I think I saw somewhere that there are gears available. However, you are right- based on what I have seen, that gearbox is bad news. I don't just say that because I have the Grubee Skyhawk II (which has worked well so far), but because I spent some time researching this both before I bought (a good idea) and after I bought (a waste of time, but I had to know). I have found no one with a good experience with the Hoot gearbox. They may be out there, but I have not heard from them.
I have heard from several people that had gear teeth break or keys sheared (the keys are apparently made from metal colored cream cheese). I will try to do some back-tracking and see if I can find where I saw replacement gears for that.
In the interest of full disclosure, I bought my SkyhawK II kit from the same vendor (bought Honda engine elsewhere). There were some delays initially, but he cleared that up and got me the stuff I ordered. That being said, I have seen his interaction with others, and it is not pleasant, so even though I had a decent experience, the best I can say is- be cautious.