Report Builder Enhancement Request - filter on sheet name

I would like to run a report on tasks per employee assigned with in a workspace.  This is pretty straight forward and easy to accomplish.  It becomes difficult to do when the sheet count for a work space goes over 250 sheets.  In my workspace, we typically have 15 sheets per clients, and with over 20 clients in a workspace, that puts us over the 250 threshold for “reliable and consistent” report building.  However, the actual sheet count that I need to pull against in the workspace is only (2) sheet per client, roughly 40 sheets, which is well under the 250 sheet threshold. To do this, I need to actually check each and every specific client sheet, and when new clients come into play, I have to make sure they are added.  This is very tedious.

In the report builder, specifically in the “where” section, I would love to see a “contains” filter for a sheet name. This could drastically reduce the work load put on the report builder.

in the meantime, I will rethink our folder structure to re-organize these task orientated sheets. 

Thanks!