Arizona SBI Tax Return | Arizona Small Business Income Tax Return - ADDITIONAL

Follow up to my question I posted a few minutes ago:

 

Electing to file the Arizona SBI Tax Return is optional.

If you elect to file an Arizona SBI Tax Return, you have to file two tax returns; regular tax return and the Arizona SBI Tax Return. 

We noticed significant increase in tax refunded from the state of Arizona if electing this option. 

But what are the trade-offs?   What are the disadvantages if making this election?

Can't believe the state would just recognize and provide small business taxpayers (Schedule C, primarily with SE Tax) a significant tax benefit by choosing to file the Arizona SBI Tax Return.

Advantages (other than decreased tax liability)?

Disadvantages?

What's the hitch?

Help. 

Thanks in advance.