This could be used for when you want to easily install an extension that isn't in the chrome or firefox extensiosn store. Normally, you would have to download the extension, then take multiple steps to install as a file. Using the URL scheme, you could turn this into a one-step process.
Using the URL scheme, you could also easily open up some common windows, such as preferences, extensions, passwords, etc. This allows you to launch Orion and modify stuff there, without having to go through the process of launching orion, and looking through the menu icons.