O.K. - Once again BW is not here to offer her expert knowledge on the subject, but I'm pretty darned certain she prebakes the pie shell, cooks the filling separately, an pojurs it into the shell to cool and set. Don't recall her ever having any liquid in the pie. Then I guess she pops it back in the oven to brown the merengue. ( Lemon merengue is among my favorites, and she makes coouple every month.)
She makes the filling from scratch, so Jello's version may behave differently.