I know this is probably of low priority, but I think I know why the cumulus gadget hangs if you use the local file, but I am not a programmer, so don't know how to fix it.
Does your code include a routine that states if NONE of the displayed elements changes then DO NOT update, because it seems to be looping after executing, and doesn't resume
Perhaps if true you could change the code to ALWAYS update, it would stop it happening
I've modified my gadget.js and index.html files to include the wind run on a 2 minute update and it has been working for about 5 days now
Then again I could be talking out of my backside!!!!!