Use noscript. It's possibly one of the best add-ons out there now.
Settings -> check 'I am an advanced user'. You should now be able to block 1st party, third party and inline JS from executing and save on a per-site basis. Hope this helps someone!
With some effort javascript from known sites could be fingerprinted and vetted.
An unexpected change could trigger a warning and blocking.
But with WASM we are really in trouble.