I have 4 filaments in a large box (with desiccant and a reptile warmer), all rolls hanging on a broomstick in the box. The design and parts are somewhere on the web. Each filament roll has a 3dp fitting that connects to a push fitting and then a length of Capricorn tubing, and I pass the tubing through a hole I drilled (very badly) in the back wall of the enclosure, with a little clip to ensure the right length is inside the enclosure.
The tubing for each of the unused filaments is coiled up and held with a hook/loop strip.
I printed a new part for the feed plate (I think referenced somewhere here on the forum) that accepts a push fitting for the tubing. The plus about this is the box can be anywhere - up, down, left, right. Yes, you have to spend some money on tubing and push fittings, but you’ve bought a snapmaker and enclosure…
This seems to work well, it is printing fine and I can feed the tubing either to the snapmaker or the little Flashforge I still use from time to time.
Adapter file located here SM 2.0 Enclosure Spool Internal Front Mount by kyle021887 - Thingiverse
That’s exactly how I set up my spool within the enclosure. Works a treat 
If you try using the adapter I designed, you can adjust the angle of the spool. I have bearings on the spool holder. Sometimes I want some drag on the spool and the adapter helps
Thanks, I’ll check that out
Another solution if you want: https://www.thingiverse.com/thing:5012319