Find the LOM.Navigator device - it's really great for poking around the API with whatever set is in front of you. I used it to put the following together to toggle MIDI track inputs with remote controls instead of diving into them with the mouse every time. You can use the same principle to accomplish what you're after.

current_input_routing, current_output_routing on a Track object

Thank you very much, guys, that's what I couldn't find. I'd been using this:

to do my API/LOM prospecting, and for whatever reason, it doesn't resolve an API path for that particular control. Also, I'd been searching the web/docs for the name of the control (see this thread title) that comes up in Live's own context sensitive help. My fault, should have just read through the entire LOM again. Of course, now there's another problem: Trying to observe a clip's record status and using that to switch audio routing is causing a big delay, due to, I'm assuming, the necessary deferlows. 99.9% of what I want to do w/ Live4Max relies on changing things based on notifications. aaaargh....

Maybe not in this case, these are not intended to be automated in real time and will possibly take time and click/pop when changing... That was certainly the case in L8 and haven't heard any change for 9