EDIT: Oh, you’re on that thread too. 
You might also be interested in @Hauke 's peek into Snapmaker’s mind on this thread regarding the Snapmaker 2.0 screen:
Granted the history of these two printers is quite different. But they surely have some in common.
As noted by @Mechanikus tear down, filament runout on the J1 is a rather unusual affair. The hardware is a Snapmaker special, using a rotary sawtooth signal to count steps.