After spending time on the phone w/an agent from Turbo Tax, I was told that the product Home & Business does not support attaching a PDF and that only the "Business" product does. However, when I removed the Safe Harbor election it still allowed me to label the businesses as Qualified Business Income (QBI) and didn't effect the bottom line at all, as I'm told sometimes it doesn't even add anything. Now I can e-send.
Hope this helps someone.
