“What does it say in subchapter B of chapter 68?”
You’ve asked the pertinent question which no one has addressed. I’ve looked into it and the answer is that you have to be an experienced Tax attorney to understand the interplay between Sec 5000A and Subchapter B of chapter 68
It does appear that IRS enforcement is limited, but I don’t know if it’s limited solely to offsetting the tax from refunds.
My final bit of advice: Don’t rely on FR posts for tax advice.