@Just-Lisa-Now- 

Well, it's worked for me for the last 30 years or so.  Do you know LEM?  That's the Law Enforcement Manual where IRS hides all the good stuff, including the tolerance for ES penalty assessed by computer.  At least I think it's in there; they won't let us see it.  They might have raised it from $100, but it hasn't been too long since I saw one for $103.  

Sadly, a lot of practitioners are part-time revenue officers, helping IRS collect $43 here and $67 there from clients who would never have to pay the penalty if they did their own return.  

Then there are those who don't know about the first-time free-pass abatement on late filing penalties.  And the "supervisory approval" requirement on the 20% Section 6662 negligence penalty.