Please consider adding a setting which informs the update server that the user wants to update to RC versions (like Mozilla does).
This would be a deliberate choice from the user (all other users would be by default in the Stable update channel)
This setting will allow a user to update e.g. from 220.127.116.11 (regardless of if it is the previous stable version or any previous RC) to 18.104.22.168 (again regardless of the release status)
Sounds like a good option to have. Going to mark as NEW and leave as a medium enhancement request. Thanks for the suggestion