Summary

I'm buying filament in 1kg spools, but my printer holds 0.5kg spools, so I always have to rewind the filament from one spool to another. It isn't convenient nor fast. So here is my solution. Adapter fits on the regular hexagonal drill bit, the rest speaks for itself. Use adapter to hold and spin one spool, and your imagination how to hold another spool.
This particular adapter works for both spools that came with FlashForgeDreamer2. It may not work for you as there are too many kinds of spools out there, but it may give you an idea for your own creations.