Karl Popper's Paradox of Tolerance wasn't simply an argument that you should be intolerant of intolerance. He actually made an antithetical augment that we actually do need to tolerate intolerance until the intolerant are actually using physical force.
If we don't tolerate the intolerant, we're not tolerant. That's the sad reality of the world. Popper got it.
Intolerance of intolerance isn't tolerance. Intolerance of intolerance is just intolerance. You can't call yourself "tolerant" while remaining completely intolerant of intolerance. I'm tolerant of Nazis and Marxists existing. I'm intolerant of their intolerant ideas. Those are different ideas and entirely compatible.
There's almost no virtue in being intolerant of intolerance. Being tolerant of intolerance is what makes you a strong person to a point. Yes, we need a spectrum of tolerance; but, we can't just settle on being intolerant of intolerance.