The IO recorded this for me on file on the computer not passport, She told me though. I went to get an extension and the IO read it out to me. However I left for 2 months and entered with a ED visa yesterday - nothing got asked. I know I entered on a visa which wasn’t a TR but I expected a few questions if they saw that ..i assumed it would create more scrutiny. A friend of mine was questioned leaving too.. but he entered the next day and nothing got said.
I don’t know if this is correct but when I filled mine out I put 90 days because that’s the visa and although you get extensions they can be denied .. but with 90 days I put .. mine all got accepted 🙂