This UI quirk has bugged me for years and I assume there's a reason why it's persisted all this time, but I couldn't find a previous discussion. I encounter it pretty frequently.
Why is there no "cancel" option when you go to create a new device? Say you choose a device type, and for whatever reason you change your mind...maybe it couldn't sync, or something wasn't right. You close the dialog box without any actual device set up, and you end up with an greyed-out "new device" in your devices list that you then have to find and manually delete.
Along similar lines, I'd love to see some (any?) work put into UI improvements...Indigo's UI hasn't been updated at ALL, in the ~10 years I've been using it as far as I can recall. The plug-in update feature, and showing Delays in the Action list, are the two lonely improvements we've gotten. Simple things like multiple conditions in a Trigger (e.g if ANY of these are true AND ALL of these are true), to re-ordering Actions with drag-and-drop rather than clicking an "UP" button 23 times, or at minimum inserting the new action below the currently-selected one, etc. Control pages layout design is pretty clunky. Ugly plug-in configuration windows with poor sizing. This is a modern Mac app that still looks like a Windows 95 app.
I know there's workarounds for this stuff and obviously what's most important is the guts, not the packaging, but it would be great to see SOME effort put into UI improvements. At least a few of the more annoying items that we've all just learned to live with. Matt/Jay -- is this stuff on the roadmap, and if not, why?