I cheat and use Spar urethane. Goes on easy, comes off easy and lasts for years in my Maryland environment even though it's out in the weather full time.
If you are really lazy it comes in a spray version. It's also cheap.
When the time comes a heat gun and scraper peel it off like it was never there.
Anyone doesn't like my finish eats elsewhere
, so far no one has not liked it.