Odd, haven't seen a hang on reboot here yet. The hangs reported in the linked thread were caused by early versions of the USB firmware updater (which updated the firmware while the system was running), LibreELEC ships with a later version where updates are performed by the bootloader (recovery.bin to be more specific).
In LibreELEC settings you can't reflash the firmware if they are up to date, but you can do it manually via ssh if you like. LibreELEC includes the rpi-eeprom-update tool (same tool as on Rasbian) and you can also use it to install beta firmwares (do that at your own risk though).
To re-flash the USB firmware use the "-u" option of rpi-eeprom-update