Glue under the thumb? Isn't that uncomfortable?
I try to keep mine at a decent shape, but because I also play electric I have to keep them slightly shorter.
In fact I hacked them off the other day because a song required me to tap harmonics and the nails kept getting in the way.
http://www.condehermanos.com/portadai.htm
very cool guitars. which model is yours?
I think you are going to find this forum very interesting. (thats not actually a good guess, I bet everyone finds it interesting...)