May well be that my USB-C hub, or my sys-usb qube, is to blame in my troubles with the Librem 14. Using everything straight off the laptop made it through a day of repeated Buildroot builds that flexed all my cores for more than an hour at a time.
@rbrown bumping up the RAM in sys-usb didn’t help, and I bounced the VM without checking dmesg and friends. When the screen goes dead over USB-C it also takes out charging which I believe contributed to my dead machine symptoms. At present I am just not using the USB-C hub with my Librem 14. It has enough native ports to suit my needs, but I may try just a dumb hub with no more than PD pass through and USB3.1 ports to see how that goes. Charging itself has not been a problem directly on the port