It sure is easy to knock the straw out of that scarecrow, isn't it?
You said what you said, so don’t disavow it after the fact. Here it is again, your words:
Unfortunately, I am governed under SSTS and couldn't avail myself of this method.
If you take this responsibility so seriously, then it doesn’t matter if dollars are big, small or tiny. It’s principle, you say.
And as to this:
I would prepare the return with an estimated 8615 and move on without hesitation.
There is no basis on which to make an estimate here. So whatever estimate you come up with has as much justification as an estimate of $0. As an additional attempt at compliance, it has been offered up to use mom’s tax return information.
So at what dollar amount threshold am I safe to ignore professional standards?
You have to use professional judgement, hence the difficulty that a strict and absolute constructionist faces in attempting to answer it. Your “principled” position has left zero room for professional judgment.