As you said, we’re working on it! It’s in our latest beta and we’re really liking the way it’s shaping up. It’s incomplete in its current state and you can expect it to become more full-featured before we release it. I will link again to Experimental feature: Smart Layout in groups to encourage everybody to give it a go 
I can’t tell you when yet, but it’s on our list. First step we’re tackling is building a prototype player which is in theory capable or more ‘localised’ changes, which is currently in development. There’s little point in Symbol Variants if they’re not supported in Prototypes. So keep your eyes on the forum for further developments in this area. 