From just a couple of minutes in the iLive editor, it doesn’t seem like this is possible, and to be quite honest, I’m not sure of a situation where one would want to do this.
Of course the work around is to assign one user key to the left side and one to the right. Then just tap them separately and save that setting to a scene. Another way to do it is to link both sides of the delay, tap it out during rehearsal, then go back into the FX, unlink the two sides and adjust the right side manually until you have double the required amount. I would then save that to a scene that just scopes the FX change.
I know this seems like an arduous process, but I think it’s the only way to do it for now. This might be something for the iLive/GLD developers to look at possibly doing.
Scott