Just tried it with the Product Hunt design file - really cool stuff. Seems like it will be very useful in quickly making realistic preliminary wireframes using design patterns and UI elements pulled from other popular apps.
I can see myself Frankenstein-ing an app design using components from many different popular apps. Ex: "I want an app that has a home page feed like Product Hunt with posts like Instagram but text editing like Notion and comment threads like Twitter" and being able to quickly pull - and adjust - those components to mesh together.
Gonna keep playing with the free version for now but looks good so far!