I think I agree that this should be clearer. We definitely don't want to do anything that prevents you from continuing to interact with a panel while data is loading, but there are two ways to know:
- In the title bar for a table, it should say "Retrieving data."
- A cell that is involved in a running query should have a little yellow indicator in the upper-right corner.
Hopefully that will help for now while we look at ways to improve this.