Limitations of BPC

Are there guidelines for number of evgets that should be in a BPC template?

We are running BPC NW 7.5 SP15

I have a user with a template that contains 83 sheets , with 644 rows per sheet. In the template he attempts to retrieve financial data for the previous 11 months. To further complicate matters there are links to other spreadsheets in the template. The template is using EVGETS to retrieve data. When he executes "Expand all" the data may or may not be populated. If data is not returned he simply runs the "expand all" again. It may take multiple attempts before he gets data.

It takes 5-10 minutes to load the template into BPC - it takes another 5-10 minutes for the "expand all" function to run.

I believe the template is too complicated to function properly, but I need facts / guidelines to back up my suspicions.