What’s the difference? SIGINFO asks the program what it’s doing and displays it. Anyone is welcome to put a layer on top of that which polls (with SIGINFO) in the background and displays any changes.

As long as the signal is built, like any good interrupt code, to only do message passing instead of blocking work then there won’t be any performance issues. We’re polling between a handful of local processes that are in the order of human-computer interaction, not polling remotely in a large scale way.