Don't know what you exactly mean. If you mean that if the manager can check already installed mods, that's impossible, the mods don't have any type of ID or Download URL when you extract them. If you mean that if the manager can open a manually downloaded zip file and install it, yes, I can add the option, but would be impossible to track updates for the same reason, the manager don't know where to check for them. You have to manually tell the manager what URLs have to check and it will download and install files in there, and internally will link the files extracted to the URL so it can check for updates and remove the files before updating.