Hullo,
Noting what looks to be a bug feature. Cant find mention on a quick search.
When adding a 'Button' component in perspective, if its enabled property is set to false, it still renders as active in the designer. To see its disabled state, the preview mode has to be entered, or the live project opened.
Pretty trival, and might be as intended! But thought I'd note as a nice to have 
Alex
Pretty sure it might be because otherwise you wouldn't actually be able to click on it to select it
This is a very good point!
But when 'designing' it should still be selectable as an object as we're not trying to push the button unless in preview mode (or at least in the project brower )
Right, but the design interface in Perspective is still a web browser, and subject to web browser limitations. It's part of the contract between web browsers and web pages that an element marked as 'disabled' can't generate click events. We'd have to 'fake' disabled state in the designer somehow, which introduces a new problem: "why does my disabled button look different in the browser than in the actual user session?"