In general, all synthesizers are distractions from the essentials of music: listening and performing. They replace that with poking around at knobs and setting modes and it does give results, but it can feel really ungrounded when you haven't trained to get any of it to go through your hands directly. I have an FM-1 and yes, it's fun. But I would say the grooveboxes are roughly equal to DJing as a practice, which is to say, they definitely can inspire ideas and awareness, they just don't lead you to go really deep most of the time.

The thing to do for theory is basically to work on paper more, take careful notes and look for connections between one kind of theory and another, because often something that seems complex one way is simple in another. A groovebox can do this by presenting you with a palette of stuff that sounds good, and then you can go about breaking it down and studying it by hand.