Looking at the schematics of the Boron, it looks like the Enable pin will not only switch off the 3.3v output but also the Modem?
So if I want to shutdown some peripherals getting their supply from the 3.3V output in order to save energy, it will not only stop cellular connectivity but also prevent any fast re-connection or remote wake-up as is the case with the Electron 3G while in “network-stand-by” mode. AmI getting this correctly?
I’m looking forward to see more details about Boron sleep modes added to the docs.
I believe your interpretation is correct.
While depowering the cellular module isn’t helpful in your case, I believe it follows the optional case here:
The EN pin is an input to your Feather Mainboard and must be used to depower the 3.3V output. We tend to tie it to the Enable pin on the 3.3V regulator, with a 100K pullup. It does not disable VBAT/VUSB, see above for a circuit that will let you do that. It is OK if you decide to have EN de-power USB/BAT as well, but not required.
On the plus side, you’ll be able to completely power down the MCU and the cellular modem by pulling the EN low, which could be handy from a custom watchdog for absolutely resetting a remote device, the same as removing all power.