I'm doing it now. It works great. I simply name any AxeFx presets with the prefix "Ax"...like "Ax Plexi"...."Ax Twin Reverb"...etc. So when I scroll through the banks and presets I know what is where.
I have tap tempo sending, the expression pedal sending, toggle scene 1&2 (I only use two scenes per preset right now due to programming limitations).... toggle individual effects blocks and of course it sends the Program Change number upon selecting the preset.
What would be great is if there was two way communication so the state of the effect blocks would update Helix led's when you change them from the front of the AxeFx or your DAW sends a change, etc..
Also, when switching to Looper Mode, it would be great if the stomp switches that are designated for looper control could have a separate cc#'s assigned when Helix is in that Looper mode than those switches are assigned when they aren't a part of that mode.
Also, if you could assign more than one cc# to a stomp so you could program 'scenes' properly without having to use the AxeFx scene paradigm. The AxeFx looks for cc#34 followed by a the scene number to specify which scene you want.
Over all it is working really well and has lots of flexibility. It isn't quite as good as the LiquidFoot+ controllers but then they can't provide great amp modeling, USB audio/midi interface and analogue and digital routing like Helix does.
I didn't buy Helix to 'be a controller' for the AxeFx. I bought it to see if it sounds good. It does. Since it also does these other things really well it is also the hub of my sound and controller for numerous devices....S Gear and Fishman Triple Play into MainStage 3....AmpliFIRE...AxeFxII. It has really cleaned up the rig and made more time for being creative instead of time spent swapping cables in and out of devices.