How can you talk about
What, me or the author of that article?
I tried LibreJS some time ago as a way to further filter assets behind uMatrix. And, at the time at least, it was cumbersome. LibreJS may have since improved their interface but I haven’t revisited it.
JShelter has been more up to the task of limiting and sanitizing allowed javascript. I also recently evaluated an addon “Policy Control” which allows the completely granular whitelisting of each individual javascript (+ other assets).