@Robert-Olson small update:
managed to add reload functionality into :
http://3d.hrg.hr/jscad/three/threejscad.html
just drop a script on to the screen, edit in your fav editor and see results.
tested only in chrome, to se errors use browsers console F12
it is a rough prototype with ton of scrappy code, but works relatively ok.
modeling is in main thread, so if you create an infinite loop, you will have to kill the tab.
nevertheless if you do start using it, let me know how it works for you , or if it breaks