>With the advent of CPU-architecture-based side channel attacks (Meltdown and Spectre are the most publicized.

I thought they repaired since 1.5 years when they let it to the public (inside Microsoft some knew about the danger)

Is it still a threat?

what are people's experiences with NoScript vs uMatrix? i switched from uBlock Origin to uMatrix, and that works pretty well and can block e.g. iframes, too. but i'd be open to blocking all Javascript, which uMatrix doesn't do by default AFAIK