Yes, that was a drop down menu in the video. Play by play: I had an empty effects slot. I held the effects button. An effect-type menu dropped down. I chose the pitch category. A sub menu dropped down and I chose the analog octaver.
Super easy to use!
I agree that a full screen option would be awesome, but I know that can be difficult with a bitmapped GUI. Perhaps the final version can have an option for an alternate larger GUI for 2K to 4K HD screens. I can see using a small GUI when recording to save desktop space and a large GUI when using the amp stand-alone.