Love to read stories about Immigration and how people do react if they have no clue. And I do not care if snowflakes tell me to leave or have to be ignored.
Have a valid and genuine passport, have the visa printed out, have the TDAC done.
and if asked just talk with the IO about things that matter.
as seen earlier, your private life, partners, previous visits, the purpose of being in other countries are non relevant but may be nice to talk about with a coffee at another place.
IF it is really 210 days and not the normal maximum 180 days, you have to get that stamp corrected.
Thanks for ignoring those who tell ignore without any advice or knowledge about visa rules. some are angry because they ask advice but not like to hear the rules.