This has been implemented to make sure no scripts is left hanging under the io process. If the script sends something to stdout, it should not be killed.
All those timeouts etc. are somewhat blurry. I'm sure dark will change / fix those at some point before 1.0
Yep, those thing will get documented soon enough I'm trying to get xmas release (remember 4.9.x .. or was it 4.6.x ) And it's going to be even bigger than that release was.