Wow, this says more about the agent orchestration tool ecosystem than what you might think, that they're unable to kill child processes they themselves spawn makes it seem like they have zero clue about what they're doing.
Probably why my impression always end up with "Wow, what a vibe-coded mess" when I look through the source of all these harnesses, they don't seem engineered at all.
Yeah, at the bare minimum these projects could also use something like portless[1] which literally maps ports to human- (and language model-)readable, named .localhost URLs. Which _should_ heavily alleviate assignment of processes to projects and vice versa, since at that point, hard-to-remember port numbers completely leave the equation. You could even imagine prefixing them if you've got that much going on for the ultimate "overview", like project1-db.localhost, project1-dev.localhost, etc.
puts 'usage:'
puts 'murder 123 # kill by pid'
puts 'murder ruby # kill by process name'
puts 'murder :3000 # kill by port'