If the issue is getting the irb player to play the notes, you could try Bbsus/G and see how it sounds to you.
You can enter Gm7#5 using the keypad for the performer to read/play, it just won't be recognized by the irb player.
You can also enter your chord as an alternate.
Thanks Bob, but I'd like to know if there is a way to enter the chord so that the player can recognize it. Otherwise, is it possible to ask the developers to add it? This is a common chord.
Cheers,