Just play it safe and bring the cash. Ignore all the "maybe" or "if you" comments. I'm on a retirement extension of stay so not a target but still brining the 20k baht when I return next month.
if you say rarely enforced you have not been keeping up to date of late. Not good to be throwing a false sense of security to people. It's the law so you should advocate bringing the 20k cash vice taking the chance.
Not sure about that but like three people came on here for help last week and said the 20k on hand was required. They were detained for hours. They wouldn't even let them go to an ATM machine to get the money.