BUMP BUMP BUMP.
This feature seems like low hanging fruit for SS to implement.
I'd even settle for an easy way to download each file one at a time, but even that is a UI disaster. It's actually easier for me to do this from the website as published than it is from the assets folder. How does that make any sense?
Squarespace has done such a good job with making most of their interfaces easy to use, if a bit complex, but certain things like being able to download your own files is practically impossible.