I think I've solved my random Channel Exceptions. I updated the bios on my EP45T-UD3LR from F5 to F10. Not sure why that fixed things but I've been crash free for 3 days now during lots of gaming and regular use. Going to keep on testing to make sure. I was also using a F5 specific DSDT and am now using a F10 bios specific one.
I'm not knowledged enough on DSDT hacking to understand the differences between the two DSDTs but I can post them here if someone wants to take a look.