Any chance ,
Rather than the preview rendering being switched off when using Javascript, Whisk could execute the javascript and show console.log output results in the preview?
I often create a blank html and the run JS within in that to test code snippets..
I actually was also just creating blank Hype Projects to do the same.
I know I could also probably use the browser console directly for this.
But that comes with its very own limitations and using whisk for this makes more sense.