I just wanted to follow up your problems with the MultiFX. Did you message Robert about it and was he able to help you out?
Hi! I sent a message to Robert, he said that he noticed the noise floor on higher volumes, too. He said that he is going to improve on that and he'll try to fix this in general on the future MultiFX modules. I disconnected mine from the bus cable and reconnected it again, which made the noise floor slightly better (there was probably a grounding problem,too) but you can still hear the noise, just not as loud as before. Guess I have to deal with it, it works pretty well for home recording but not perfectly when playing live because of the higher gain levels on my mixer.