Seriously, I think BEACHES would be hard to adapt for the stage. It's very episodic (it's like a fictional version of the "Then I wrote" movies about composers and playwrights), a style that is more conducive to film, where the camera itself is the unifying element.
Stage plays are unified by elements like plot and character. ("Unity", per Aristotle, is that feeling that everything that happens on stage is both necessary to advance the plot, and probable, meaning it follows logically from what came before.)
We enjoy unity in a play/musical because it is reassuring as opposed to real life, which is so often random.
This isn't to say BEACHES can't be adapted, but IMHO it will take a more radical transformation than merely singing "Under the Boardwalk" and "Otto Titsling".
All that being said, I admit that despite being a dyed-in-the-wool Bette Midler fan, I found the film mostly tedious when she wasn't singing. And to me, "The Wind Beneath My Wings" has always sounded condescending, if not an actual song about farting. Yet millions of moviegoers (mostly women, I assume) loved the movie.