Default files sub folder channel permissions

[FireEmerald]

The TeamSpeak 3 Server creates for each channel a folder inside /files/virtualserver_X e.g. channel_XXXXX these folders got 0700 (rwx------) permissions by default.
Files inside these folders are created with 0644 (rw-r--r--) permissions.

For me that's a problem, because our backups are performed from another linux user which is inside the same group as the teamspeak user account so that he can access all files from teamspeak expected the new created folders by the TeamSpeak 3 Server itself.

Is there any possibility to tell the TeamSpeak 3 Server how to set the folder permissions? e.g. 0750?
Or is it somehow possible to set a bit or something on the top-level teamspeak 3 folder to grant access to group users to any sub-file and folders?

Best Regards