Looking for info about the accessibility of Sketch interface creation app for Mac OS

I am a senior accessibility tester for Temple University. I'm trying to figure out how accessible the Sketch Mac OS app is for VoiceOver. Does anyone have any experience with this app? I have taken a look at the app with VoiceOver, and a good bit of the interface seems to be accessible, but I know nothing about this kind of app, so I was hoping to hear from someone with real-world experience with Sketch. Their are a number of unlabeled buttons in the app's interface.

I would also be interested in hearing from anyone who has experience with other apps that are used to create interfaces.

By the way, here is a link to Sketch, which you can try for free for thirty days.
https://www.sketchapp.com/

Thanks

Forum: