Bryon,
If I had to guess, the reason why it is not working is because you are not understanding how it is supposed to work. The 4CM, while it is actually simple, is something that seems more complex and can take a bit to wrap the head around. it did for me. If you know how to assign switches then you should be able to get this working. I would start with a new preset and simply add an amp and the appropriate loop blocks... then visualize the flow of signal...
like this -- Guitar -> Helix -> any blocks before your actual amp's preamp -> send #1 -> Amp input -> Amp Preamp with all the controls -> Amp send -> Helix return #1 -> amp block and any blocks you want after your amp's preamp -> Helix main out -> Amp return -> power amp -> speakers
So when you disable the loop on the helix in a given patch the signal now looks like this --
Guitar -> Helix -> any blocks before your actual amp's preamp -> send #1 -> Amp input -> Amp Preamp with all the controls -> Amp send -> Helix return #1 -> amp block and any blocks you want after your amp's preamp -> Helix main out -> Amp return -> power amp -> speakers
Therefore you have only modeler with no preamp controls---
When you enable the loop and disable the amp model it looks like this ---
Guitar -> Helix -> any blocks before your actual amp's preamp -> send #1 -> Amp input -> Amp Preamp with all the controls -> Amp send -> Helix return #1 -> amp block and any blocks you want after your amp's preamp -> Helix main out -> Amp return -> power amp -> speakers
You now have control over your preamp AND all the effects in the blocks before the preamp and after the preamp without the amp model.
ok... with that flow in mind it works like this --
Patch setup like above -- button 1 = Loop #1 engaged Amp Model off / Button 2 = Loop disabled Amp model on
There may be more ways to do this but the idea is constant -- I honesty hope this helps.