There is only one place in the IRTPA rules that says “Unless any Local Rule provides otherwise”, which is the definition of “Out of Court” in section 1. The RMTC does have a local rule here: if a ball goes over the girders supporting the roof, but does not hit them or the roof, and does not otherwise go Out of Court, then the ball is in play.

During the Boomerang tournament, there is a local rule that if a racket is dropped, the point is lost.