Sorry, but I don't know of a solution for that. The folder gallery is something I got from codeplex several years ago and modified it to work in mojoPortal, it is what it is and does what it does and it is not easy to change it because of the way it is implemented. It is very complicated to even understand the way it works because the control is also an http handler and it works in different ways depending on the context sometimes as a control and sometimes as an http handler, there is a lot of nuance to really understand it and it is easy to break it by making changes without first understanding all the nuances of how it works.
Currently I have no plans to make further modifications to the folder gallery.
Best,
Joe