I use SIGINT more frequently in a terminal than copy-paste. I suspect this is also true of most power users. That’s why the situation is the way it is.

Since Toshy is emulating Mac behavior, I imagine that copy/paste shortcuts move from the Ctrl key to the Super key.

I don't think you understand - macOS prioritises SIGINT use by introducing a new keyboard key for copy/paste instead of masking Ctrl. Using SIGINT more frequently is exactly the point.