Tried already and no, rather, sleeping and waking is like booting the OS for power management purposes, so if I do that the devices get recognized. I can also boot with the device plugged in and turned on and it will be recognized. I guess I'll just have to fiddle around some more with the notifications, I'm bound to get it right eventually.
In practice I'll never ever use the analog surround but it'd be cool to have it. If you google, there's a tutorial on how to do it without aggregating because apparently some macs did include a setting for native 5.1 (no 7.1 though, I think). That guide in particular is for ALC889 but the principle should hold, I guess.