QBID for rental properties

In my opinion I qualify for the QBI deduction for my rental properties.

I have a couple of questions maybe someone can answer.

1. The QBID is applied to enterprise groups. I want to lump all of my rentals into one enterprise group. However, I cannot find anywhere how to specify what is in a particular enterprise group. How do I do this? Is everything assumed to be in one enterprise group unless otherwise documented?

1. In order to claim the safe harbor (which I qualify for), at one point the instructions said that a pdf signed under penalties of perjury basically claiming you were eligible to take the safe harbor had to be separately attached to the return. Did this make the final regulations? What do I do if my e-file program won't allow an attachment like this?

Thanks.