So other do not need to look it up, here goes:
".06 Procedural requirements for application of safe harbor. A taxpayer or RPE must include a statement attached to the return on which it claims the section 199A deduction or passes through section 199A information that the requirements in Section 3.03 of this revenue procedure have been satisfied. The statement must be signed by the taxpayer, or an authorized representative of an eligible taxpayer or RPE, which states: “Under penalties of perjury, I (we) declare that I (we) have examined the statement, and, to the best of my (our) knowledge and belief, the statement contains all the relevant facts relating to the revenue procedure, and such facts are true, correct,
and complete.” The individual or individuals who sign must have personal knowledge of the facts and circumstances related to the statement. "

@TaxMonkey Could the election added in screen 46 "Other Election" and the signature of the tax return would qualify as a signature for the election?

To expand on the point that I think TaxMonkey is trying to make.  You only have to attach a statement if you are relying on the safe harbor rules of N-19-07.  If you are basing your "trade or business" determination on other factors (i.e. "facts and circumstances" supported by code, regs, court cases, etc.) then you would not attach a statement.

Rick

PS: But yes, at this point I would make my own statement using the language required by the safe harbor regs and have the client sign it before scanning it to a PDF and attaching it to the tax return.  There are arguments that the general return signature covers the return and any attached statements, I'm not sure I'm buying it though since the regs specifically call for a signed statement.  If relying on these regs, I'd err on the side of caution.

I'm not sure why you all ignore Rev Proc 2019-38 which was the final rev proc on the subject issued in September of 2019.  IRS Notice 2019-17 (issued in April of 2017) is just a PROPOSED rev proc.  While the proposal contained a signature requirement, the final rev proc did not.  It just says that the original timely filed return mus include "a representaion"  that the requirements of the rev proc were met.   The notice 2019-17 says that the statement must be signed  “Under penalties of perjury, I (we) declare that I (we) have examined the statement, and, to the best of my (our) knowledge and belief, the statement contains allthe relevant facts relating to the revenue procedure, and such facts are true, correct,and complete.”  That language is nowhere in Rev Proc 2019-38