20-year Roommates -- Still Some Issues

Sorry for added post but I wanted to chime in and say that I agree with trying a shift to feeding frozen thawed. Aside from the visual/olfactory age-related problems I mentioned above that may be causing feeding problems, it is also possible that their capacity to deal with live prey has diminished with age, and that this is making them anxious.

So I'd put the possible transition to F/T feeding on your list of potential solutions here.

Why ask if you are not willing to do the one thing that would easily solve the issue? The snakes are clearly stressed, this is risky for you and them in the current situation. Because it's always been done that way is no excuse for not improving their setup and lives and stress levels. You aren't 10 anymore, you know better, so do better. I'd also assess their weight and likely back off on the feeding, two medium rats a month for a 20 year old bp is an absolutely ton of food.