O is unassigned and definitely does nothing here (latest build). I may bind it to something now that I know that!
 
I rarely use offset but am definitely interested in clever/useful/cool applications, so bring on that tip-o'-the-week Craig!

As a rule it's tricky for any app to change the "defaults" for key bindings and also let users customize their own bindings.  I'm pretty sure this default change falls into that, some older version users may very well have it bound to a key/still bound.
 
The keybinding UI also never seems to work right for me, it claims nothing is bound to commands that are clearly bound and a host of other logic defying issues.  It and the drum map editor both need serious UI improvements.