Trigger special backup of one directory by client

I know how to configure which directories to be back-upped on the client via server gui and how to manage them form the client (urbackupclientctl add-backupdir).

But I want to do client triggered additional backups for a special directory. Something like urbackupclientctl start -dirtoback dir_to_back instead of urbackupclientctl start --full.
Unfortunate the -poption is pw-file.

Following urbackupclientctl start --help there is no such option - is that correct?

Running a lot of urbackupclientctl remove-backupdir commands for all server triggered back-upped directories, urbackupclientctl add-backupdirfor the special client triggered directory and thanurbackupclientctl add-backupdir` for all the server triggered again seems not to be good solution.

The keyword you might be looking for is virtual client. Enter a name in virtual clients and you get a second (virtual) client for which you can set different backup settings including backup paths.