I have a couple thoughts regarding zooming and fitting to screen:

1. Currently, Ctrl - 0 fits all artboards (the entire canvas) into view, while Ctrl - 1 zooms the entire canvas to 100%. I don't like it that way. It feels weird, it doesn't feel natural. I intuitively press Ctrl - Alt - 0 trying to zoom everything to 100% (as I'd do in other Adobe products), but that shortcut is unused, and instead it's used Ctrl + 1 to do the same. I get it that it's shorter, but it feels wrong. Maybe using both shortcuts? Ctrl - Alt - 0 is without any use (that I know of) anyhow.

2. Some people have talked about shortcuts to fit the active artboard into view. I learned that it is done with Ctrl - 3, but some people have argued that it'd be preferable for it to be Ctrl - 0. I don't agree with this. I wouldn't want Ctrl - 0 to fit the current artboard into view rather than the entire set of artboards. The reason for this is that I don't see each artboard as a separate document; I see (and work with) the whole set of artboards as a single document.

Also, note in here: Ctrl - 3 doesn't only fit to screen the current artboard, it also fits to screen whatever element is currently selected. I find this very handy. If the artboard background is selected, it'd fit the entire artboard into screen, but if some particular element is selected (like a button for example), then it'd fit that element into screen.

I think it is somewhat pointless to make a shortcut to zoom in the current artboard to 100%, because this is already done with Ctrl - 1 (and/or hopefully with Ctrl - Alt - 0). If you think about it, it's the same behavior. Ctrl - 1 zooms in from whichever element is currently on focus. So if you're working on an artboard and you want that artboard to zoom to 100% you simply have to zoom in the entire document and whatever you were working with would be on focus. This is what I mean with seeing (and working with) all artboards as a single document.

Anyway. In short, this is what I'm suggesting:

Ctrl - 0:
Fit entire document (all artboards) into screen. This works this way already.

Ctrl - Alt - 0:
Zoom entire document to 100%. This is currently done with Ctrl - 1. This shortcut is unused (as far as I can tell), so if we're going to leave Ctrl - 1 because it is one keystroke shorter, then at least it could be made that both shortcuts do the same. Or even better yet, why not let the user decide which shortcuts he feels the most comfortable with and uses? This could be an useful addition to XD: custom shortcuts.

Anyway. I really like how XD is going, and even though there are still a lot of features missing (particularly on Windows), I'm already kind of addicted to the program. The speed with which I'm able to design is amazing. Which talking about speed...

1. The zoom in and out could be faster. I like the zoom that has Photoshop way better than the one that has XD and Illustrator. You simply pan in and out, and it is smooth and beautiful. You don't select, you just tap and drag. I think that system would fit well (way better than the one that's currently implemented) with XD's core values of speed and simplicity.