Function wanted

It will be usefull in separate listers mode to make option "auto set second lister as destination if there are only 2 listers". Sometimes i open one lister, then second, then i'm looking something on third one (so second is destination and third - source). After I close third lister, second is still destination and first is OFF. If I click on destination, lister is source but second one is still OFF.

I'm not talking about back in source/dest history when closing listers because that may be a little difficult. As I know, locking lister as destination is not possible too, so maybe that little option to auto set destination lister if only two of them exists will be useful.