Just to mention it:

Updated a Sony Z3c running #CarbonROM and upgraded a tablet running #LineageOS. Thanks for all the people who build these systems!

It took me about two hours to

• get the backup on the Sony working in twrp with a sdcard
• do full system backups
• update CarbonROM manually, because the reboot into recovery doesn't work
• getting a stable usb connection to the tablet by rotating ports, cables and orientations of the plugs
• install a newer version of recovery.img on the tablet
  • needed to recap how this is done in Linux using heimdall
• install the newer LineageOS via adb sideload

Looking back at the process I prefer much upgrading my #Librem5 and I need to get back to the idea of getting a #Librem11 to get rid of the dependency on the LineageOS tablet.