This is one of the differences between the PinePhone and Librem 5. They both have hardware switches for the modem, however the modem can be removed entirely from the Librem 5. I wonder what the hardware switch in the PinePhone is disabling. Is it power? The modem module on Librem 5 adds about 5mm in depth compared to the PinePhone and has the switches on the outside. The switches on the PinePhone are under the back cover and fits with the use case of setting it and not touching it again — could even epoxy it.