Yes i have it on the V3 and works fine (but don't find the folder / files where is this icon 2 Gears)

And for the V4 all seems at the good place ( -80 Extscripts.html, 81 ExtScriptFull. html etc...) on the Appdata but nothing on the Bottom Bar for launch it! (but don't find the folder / files where is this icon 2 Gears)

I have the Custom Scripts who works fine also with 2 Gears on the Bottom Bar

all that is a little headachess :)
I had made a big tutorial about that in the past! :)
http://moiscript.weebly.com/customiser-lui.html