PinePhone: Modem firmware updates
Many PinePhones shipped with modem firmware that is now outdated, and it's likely that future PinePhones will do the same. While it might sometimes be fine to stay on older firmware versions, my understanding is that these older versions have issues with modem suspend which as a result makes receiving incoming calls unreliable. It's also generally desirable to keep up with recent software as this might include security fixes and so on.
To my knowledge the only way of updating the modem's firmware at the moment is via a tool called qfirehose[1]. Although the source code is available[2], it seems to be proprietary going by the licence headers and it is not clear to me whether this source code has been legally shared onto GitHub. Regardless, as discussed on Matrix, postmarketOS should somehow ensure that the PinePhone modem's firmware stays up to date, or at the very least offer a way for users to update the firmware easily.
Also worth noting is that Martijn Braam made a GUI frontend for invoking qfirehose[3].
Instructions on how to update the modem using qfirehose can be found on the Pine64 Wiki[4] and the Pine64-Arch Wiki[5].