Mitmproxy/mitmdump multiple processes using same proxy port


I noticed that it is possible to run multiple mitmproxy/mitmdump instances on the same proxy port.
As I don’t think that this is a valid scenario (as it is totally indeterministic which process processes a request) so why doe mitmproxy not lock the used TCP port so that the second and third instance is getting an error - or is there an option to enable such a behavior?

Edit: I noticed that this behavior is hard-coded and cant be changed without modifying the code: