The intro to r/essential states in part "We're here keeping the lights on with home brew and even some user built custom hardware." This makes me wonder about additional features hanging from the magnetic connector on the back.

Does anyone remember the Handspring product line? A Palm Pilot with an external connector. These were designed by Jeff Hawkins and Donna Dubinsky, founders of Palm, after they left Palm and founded Handspring because they were unhappy with the direction the new owner was taking the company. (Does this sound familiar?)

Handspring provided a complete description of the external connections and dimensions for the snap-on features--everything you needed to build an add-on device, called a Springboard.

Does the same exist for Essential? A software and hardware developer kit? Reference manuals? A circuit breadboard with the magnetic connector would be a neat accessory for initial development without a lot of investment.

Some things you could do with it.

Wired Ethernet

Logic Analyzer

Oscilloscope

Specialty measurements and surveys (airflow, radio frequency, radiation, chemical, etc.)