Thanks for the suggestion!

We tried out the X1200 testing firmware: openwrt-x1200-3.100-1218.tar which appeared to improve reliability of the router. We looked through a diff and had noticed the exact changes you commented on above! The testing firmware initially appeared to fix our issues, however I heard the device finally entered this bad state again today. That means it stood up for about a day and a half (an improvement on the 20-30 minutes window we previously saw with similar activity).

I will try making your above changed on the 3.027 firmware next week and report findings,
Thanks again!