The Launcher functionality is fantastic at present and getting better all the time.
An increasing number of users report having issues with duplicate mods - i.e. mods that exist both as SW subscriptions and as manually downloaded local mods. To address this a useful feature would be for the Launcher to check for local mod duplicates ie. locally added mod and SW subscription - then prompt the user to select the mod to retain. Perhaps the rejected mod could be deactivated via renaming etc. (rather than deletion as a safety option or prompt user for deletion). The decision would need to be up to the user - given possible missing mod version / naming issues.
Another really useful feature would be for the Launcher to search SW mod submissions and offer to replace the existing local addon with the SW version if found - assuming it is the same or later ver. The Launcher would then deactivate the non SW mod as above.