Hey Jonathan -- happy to help if I can... I have the buttons controlling my Golden Boy on a separate "Gain Settings" page, which is different from the out of the box "Loops" page on a PBC10. I have some other buttons on the same page, controlling all my (current) gain pedals and suchlike, including the different channels on a BluGuitar Amp1.
On the Golden Boy, you can control bypass for the drive and boost individually, as well as 4 different clipping options on the drive and 4 different "flavours" of boost, and 4 different levels of gain. So I have two buttons which turn on or off the drive and boost (respectively), an IA cycle button that cycles through the different clipping options, another IA cycle button to go through the boost flavours, and a third IA cycle button to cycle through the different gain levels. Key thing is that all those buttons are set to "send on preset change" and "update on preset change". That way, I can store those settings (button states) for any given PBC preset. So when I change PBC presets, the Golden Boy will switch to the settings I need. Hope that makes sense...
From what I know of the CB Preamp Mark II, I suspect there's lots of different things you *could* control with different IA buttons. My sense is that the key thing would be to set up a page where you program buttons to control the things you want to control on the CB Preamp.
If you don't want to set up a whole separate page for the CB Preamp, say, to keep all the pedal/loop bypass buttons on the "Loops" page, you could combine a couple of loops into an IA cycle button. For example, the button labelled 5 could be an IA Cycle controlling loops 4 and 5, where step 1 is both loops off, step 2 is loop 4 on, step 3 is loop 5 on (and loop 4 off), and step 4 is both loops on. Then the button labelled 4 could be an IA button that turns the CB Preamp on and off via MIDI. That's just me speculating -- I'm sure you could do more, but the closest I've come to one of those CB Preamps is watching "That Pedal Show" on YouTube...
Hope that helps. But let me know if I've only made matters worse!