The setcommand is defined as:
This would imply that the -nobackup-file option would be set for the entire storage, regardless of the repository. I suspect (and hope), though, that I can specify a nobackup-file in one repository but not in another (or use different file names in the two). This would mean that the help text for the set command could be improved to say something like “Change the options for the default or specified storage or the current repository”
A more fundamental thought would be to add another command for configuring the repository while limiting set to storage parameters only.