It's not you, it's us. As @stewarts16448458 noted, we need to fix/improve it on our side and I've logged it internally as an issue.
That said, even when the Custom Event event type begins to support detecting custom events dispatched off the window object, it still probably won't detect events triggered using jQuery (e.g., $(window).trigger('email_submit')). This is because jQuery has its own eventing system that's separate from the native eventing system. Launch only detects events created using the native APIs and doesn't cater to any particular library like jQuery.
BTW, I spoke with Aaron at Adobe regarding this. He confirmed that it does not presently work on window (document is the top level object at present). He confirmed that listening on window would be desirable and that he would make the case for a fix. At some point in the near future, you should be able to remove that patch and start listening on window.