Impossible to update a v3.0 device -- I just tried on 2 brand new v3.0 devices (with Red interface).
@VLud keeps saying "it's user error" and closing my bug/issue, but I have successfully updated v2.0 devices. The v3.0 devices cannot be rolled back -- it says updated successfully (doesn't seem to install the firmware -- U2W_Update_2020.11.10.2138_ROLLBACK.img -- renamed to: "U2W_AUTOKIT_Update.img" as it does it in like 5 seconds). But, the internal webpage does show the rollback version 2020.11.10.2139, however, the interface is still the red one, not the green/blue one. But then, when you try and install the CFW (any version, but has to be named "U2W_AUTOKIT_Update.img", "U2W_Update.img" does nothing) -- it shows "Update Failed".
You can however, update to the latest official from the GitHub and then downgrade/update... but CFW will not install on a V3.0 device.
More people with v3.0 devices that want to install CFW need to 1) try and confirm my findings then 2) ask
@VLud because he doesn't seem to think it's an issue. I have been trying all combinations for a couple weeks now with no success...