[_puk]

Funny that, my experience is quite the opposite.

Nexus 6P (Marshmallow); any time I lost phone signal the messaging app would get itself stuck in a tight loop until it had to be force stopped. You'd think they would have tested that on a brand new device..

Cyanogen Mod has been great in the past, as you say, to extend the life of old phones. Quite stable too.