I develop custom solutions for multiple clients. When I am debugging or monitoring these solutions I will be looking at different variables, tables, layouts etc.
Some expressions can be complex and/or ExecuteSQL commands. If I have expressions in the Data Viewer I want to keep there for a client that refer to tables that are not present, or have different properties from the solution I am looking at it will naturally have an impact on performance and may even result in a crash.
If I could create 'eta' of expressions I could load the appropriate set for that client.
This would also have the advantage that, in the event of a heavy crash, I could restore the expressions I had in the data Viewer and not have to recreate them