We've solved that problem by creating a second smaller enclosure on top. The dry box enclosure fits into screw slots to perfectly align it with the box underneath. Whenever you need to change filament, it just lifts right off.
To align with the enclosure underneath, the dry box enclosure has to match the thickness of your Prusa MMU2 enclosure. The base model dry box has a 6mm front, 3mm sides and back, and a 6mm top, while the upgraded version fits the all-over 6mm Prusa MMU2 enclosure.
So if your Prusa MMU2 enclosure has 3mm sides, order the dry box with 3mm sides. If you have an enclosure made out of all 6mm acrylic, select the all 6mm dry box.