Originally, I was only able to record about 5 minutes. After the .402 update, I was able to reach 7 minutes before I stopped it myself. However, after I stopped the recording myself, it gave me the overheating message lol.
I don't know if it was just my imagination but it felt as if my phone did not heat up as fast compared to before the update when it got hot in 3 minutes or so. I honestly don't think the update did much for 4k video recording and that I was just able to get to 7+ minutes of 4k recording due to the cooler ambient temperature. Either way, I'm able to consistently reach 5 minutes of 4k recording before and after the update so I'm quite satisfied.