Are you planning to seperate these sexually mature snakes once the new viv is complete?
"Just regurge" is a bit of an understatement. Regurging is something that you want to avoid at all costs. Snakes can regurge if the prey is too large, if their home is not warm enough to allow them to digest (remember they are ecthothermic creatures) or if they are handled or stressed too much right after eating.
Regurging their prey can cause burning inside their bodies from their intense stomach acids as well as external burning if they lay on bedding soaked in this acid that came up with the undigested prey. Generally after a regurge you have to do specialized feeding routines to avoid triggering another regurge and to allow the snake to heal properly. It's not as simple as you or me throwing up.