Question: Refresh interval and fetch strategy

I have two questions in particular:

1) Is there some way to refresh after specific intervals? Like having the entries be only valid for 7 days for example.
2) As far as I can tell the current implementation is synchronous only. Are there plans to support async requests and concurrent ones? To give an example, I am working on a project that needs to download 3k files and cache them locally. I've hoped that there was a crate that would help me out here. This one actually looks the most promising from the ones that I found. But as far as I can tell, it only fetches one file after another.

Have a great day weekend!