How about adding a feature to allow subtypes for composite fields. This would be useful to allow me to quickly visit a URL in one click, if that URL has been automatically created from another field (for example if it's one for a username titled field).
You didn't show the formula of autourl field, probably it is: https://twitter.com/[username]
You can set Copy of property of launch field, just write there field name in square brackets: [autourl]
Then, as you type some letters in username, both autourl and launch field will be filled. And you open url in browser by click on launch field right-button.