Didn’t have time to investigate (or know how to do this) but somehow think that fwupd package is something available for the first time within PureOS Byzantium repo. IMO, very good direction and great progress that required (and still do) some expert handling and control from Purism Team side, or at least deserves some attention from users of PureOS. Thank you @jeremiah! Just preparation to get there was a lot of work, wasn’t it?
Few selected explanations here (beside another 53):
And under same link address is written: “When compiled with firmware support, it will check for updates periodically and automatically download firmware in the background. After the firmware has been downloaded a popup will be displayed in GNOME Software to perform the update.”
sudo apt list fwupd
Listing… Done
fwupd/stable,now 1.5.7-4 amd64 [installed]
Short overview, all started here:
fwupd was promised to happen and from now on available within current PureOS distro:
All while kindly and repeatedly 
insisted within LVFS main thread: