Sounds like they are stressed, two snakes having to compete for heat/hides/food could make them very defensive. It could also it be that they are now conditioned to expect food when they are out of their cage. My boas are ready to strike as soon as I open their enclosures and if I don't rub them on their head with my snake hook they will tag me. They are conditioned to expect food if the terrarium door is opened and no hook touches them. I know you been keeping them for 20 years and you probably believe if it ain't broke why fix it but two enclosures erases almost all your problems. Snakes won't be stressed, and you won't have to feed them out of their enclosure.