However, your example would trigger itself over and over... at least until you got the Line Too Long error. Every echo the script made would trigger as being a "newline". This is where that event or an on ECHO event would be problematic. Obviously, you can avoid the problem by just not echoing/displaying anything to the "watched" window/channel. Even so, I really see little use because you'd be limited on what it would actually handle.
I'd rather just put the echos right into the scripts if needed.