Hey All,
I've been playing around with this the last day or two and wanted to share with everyone.
Installing modules to USB is extremely easy, I'm still playing around to ensure there aren't lingering effects as a result of the change I made.
All modules and their data are stored by the looks of things in /www/pineapple/modules. So all we need to do is move the modules directory to the flash drive and create a symlink in its place.
Steps are as follows, I'd suggest not having the web interface open while doing this:
1) mv /www/pineapple/modules /usb/modules
2) ln -s /usb/modules /www/pineapple/modules