Select multiple animation transition types for a single transition
The ability to stack animation transition types. For example: I would like to be able to have a slide transition with a dissolve on it as well.
Pretty surprised no one has been digging this yet :)
A combination of slide and opacity transitions would be very useful. Current UI guidelines on our products include many of these. They are currently showcased in html/css/js and can't be translated into XD yet because of these (and the painful absence of hover effects).
For instance, mega-menus animations are often poorly done on the web: sometimes there's no animation at all and a huge block brutally shows up on top of the page content, sometimes it slides along its full height, which feels heavy and unresponsive.
An elegant solution is to make it fade in, along with a slide effect on a much shorter distance to retain visual continuity. I can't seem to make this happen in Adobe XD as of yet.