I suppose. I've had years in the past where I had sporadic self-employment income, and I filed estimated payments only for the quarters where I had income, maybe even was late or combined a couple of quarters every now and then. I never got penalized as long as the amount I owed for the year had been paid by April 15. Maybe I was a small enough fish that they just didn't care.

Most likely you met one of the safe harbor tests.

The dunning for getting this wrong is automated, so if you didn’t do it right and didn’t pass a safe harbor, they’d have sent you a notice.