You’re not alone in the “difficulty to fill 6U”…I’m in the same boat. I love all of the modules I have now and I’m a little over half way full in my 104hp 6U Monorocket. I’ll be adding a 4ms Pedals PEG in a about a week…but once I add that I’ll be good for a long while. At some point I’d like to add a very distinct osc…maybe the Jupiter Storm.