last time we were in WDW 2008, We made it a habit one day to see every performance of the BI. They started off on the first performance of the day dressed like the early Beatles and played all of the early stuff. I remember that the shows lasted about 45 mins. For the first show there wasn't a big crowd and they pretty much called it when they were ready. The next show they evolved to the next costume and songlist of beatles history. So on for the 3rd show and the last show ended when it was night. I do remember also on the last show there was an encore and maybe even on the show before that. I definetly believe the crowd drives it. If you are asking if there was staged people in the crowd starting a "one more song" chant I definetly don't think so. So they may always do an encore on the last performance of the day but there is nothing staged about it. We love the shows and plan on going when we get there this fall!
