Besides the enviromental reasons...
It's not legal and code compliant.
Does not meet the "readily accesible" portion of code, nor the "free and clear" portion of code and working space requirements. I could go on and on of why installing inside a cubby in the ceiling is a no-no. Commercial building and drop ceiling where there is no choice and compliance can be maintained is another story.
The M1 and related components are intended to be installed within a suitable electrical enclosure. Covered within the NEC and the installation documents.
Put it this way, while the LV cabling and wiring is considered "safe" due to the low voltage and current the system puts out, the metal enclosure is there to enclose any sparks, overheating and in the case of the battery, which is unfused and capable of quite a bit of energy, let alone split, leak, heat up, etc. Yes, it is a stretch and pushing for the enclosure to help with sparks and fire, however I have seen panels and other components catch on fire, and specifically in the case of alarm panels, I've seen RJ jacks and other system components catch on fire after a surge/lightning strike.