Originally Posted by pmaddock

Not sure I'd agree with that recommendation - you're in difficult spot once you're on the FA's territory (the plane). If the FA actually used the phrase 'take your seat immediately' its probably better to give it up and start jotting notes about anything and everything that the FA might have done wrong throughout the flight. On the way out get the FA's name and then get to work on the email. To directly defy the FA instructions could get problematic as you will have to stay in FA territory for the duration of the flt.

That said I think I'm hearing that the best strategy is to not board at all if you think there is any chance of a lagging upgrade.