Hey Ryan! Definitely something I’ve been looking for as well!
I can safely say this is a feature we’d all like to see in XD.Anonymous commented
If you hit the asset's or artboard's quick command to first show panel, you can then hit the same QC again and it will hide / collapse the panel.
For instance the asset's panel quick command to show is: command + shift + y
To then hide / collapse the panel you need to hit command + shift + y again.
The again show the panel you would again need to hit command + shift + y
You can then collapse the assets panel if you again hit command + shift + y