I always thought the idea of the bank angle sensor was to help the guy who went off the road and down the hill and was pinned under a running, horizontal bike who was unconscious or could not manage to reach the key or kill switch, and gas was leaking out (and fixing to ignite).
There may be other reasons, but that's the one that comes to mind.
Whether for safety or for self preservation of the engine, I believe the bank angle sensor is a good idea.
I'd remove & test it and replace it, if necessary, with a tested used one.