never trust immigration officer !!!! Few years ago they asked me to come back to immigration office on the next day even if i had a ticket number and it was my last day on my visa. They said i will not have overstay (and it was amnestie time during covid), next day the same officer gave me overstay. So unlimited? i don't believe it (yet)
does that mean that even when a school ask us to get out of the country and come back to do new visa, it's better to do border run with an agency to increase chance to get accepted back?
my situation was at the begining of the amnesty, so different situations, but for safety reason i advise to not trust immigrations officers, and to try to go before end of stamp.
if they say you can come after the date, and will not get overstay, don't trust them! I got 1 day overstay because of them and it give me a LOT of issue to be able to stay after that.