Disable "Save" button while creating variant

While I'm walking through the variant creation wizard (on an existing panel) it's very easy to accidentally loose the changes I've made to my partial new variant by clicking "Save" at the very bottom of the page.

Since the "Save" button (at any non-complete stage of the variant creation process) won't actually Save the variant, it would be helpful if it were disabled. This way, the only actions I could take would be to either continue playing in the variant creation wizard, by clicking "Continue" or "Back", or cancel all changes by clicking "Cancel" at the bottom of the page.