Open RBO was previously called True RBO. It was renamed to dispel any notion that the other reverse categories were 'false' or 'less true'.

The run time end frame is now defined as when Aquamentus' heart container reward appears.

Thanks to a Randomizer update, Second Quest Open RBO can now be made to start the player with the Raft, allowing the bosses to be beaten in reverse order. As of this post, there had been no submissions for Open RBO 2Q.

Nice, thanks Eunos