I came across a neat script, recently posted to Microsoft's Script Center. The function, Open-ISEFunction.ps1 takes the name(s) of function(s) that are currently defined and creates an ISE edit tab for each function. It’s pretty simple in that it jut grabs the function definition from the function: drive, wraps the definition in a function/script block, then opens and adds the definition in a new ISE window.
If I get time, I might extend this function for the ISE into a menu item. The expanded function, which could as a menu item have a command key short-cut, could take any selected text and try to open the module of the same name. I’d also like to add a couple of comments at the start that might help.