At the moment devices that need to do an aarch64 > arm change like WeTek Hub/Play2 and Odroid C2 aren't showing a manual update option because the settings addon filters the list of available options according to the current device/arch. An experiment needs to be done duplicating and renaming the arm image so it has an aarch64 filename (e.g. LibreELEC-Odroid_C2.arch64-8.90.004.tar) then rebuilding the JSON data file. The update process isn't sophisticated enough to detect that the file is a different arch so it will just download/unpack/reboot/update as normal and you should get the same result.
NB: I'd go test this myself but I'm currently on vacation and can't .. but one of the other staff should be able to check the theory.