You're projecting your beliefs onto popper. You don't have to agree with him. I'm not interested in debating the appropriate nature of tolerance in society.
I really don't know how much more clear he could have been about his beliefs: incitement to intolerance is not the same as incitement to violence. He extremely plainly states that we should engage in rational dialogue if we can, but reserve the right to suppress intolerance, even by force, because they may begin preaching violence.
we should claim the right to suppress them if necessary even by force; for it may easily turn out that they are not prepared to meet us on the level of rational argument, but begin by denouncing all argument; they may forbid their followers to listen to rational argument, because it is deceptive, and teach them to answer arguments by the use of their fists or pistols. We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant.
Claiming the right to suppress them because it "may easily turn out" is not the same as "once it becomes clear".
He's extremely obviously not using incitement to intolerance as a stand-in for incitement to violence, because he says it should be criminal in the same fashion as incitement to violence.
we should consider incitement to intolerance and persecution as criminal, in the same way as we should consider incitement to murder, or to kidnapping, or to the revival of the slave trade, as criminal.
Consider the context in which he wrote what he wrote: world war two had just ended. We saw what happened when an open society allowed an intolerant right wing group to spread hateful rhetoric: they started small, got extreme, and then got violent.
Is it too much of a stretch to think he would have the opinion "it would have been okay to stop the Nazis when they were shitty, and before they got evil"?
In the aftermath, influenced by popper and people like him, Germany outlawed the entire ideology.
No one considers it counterintuitive or ambiguous if you need to tolerate people being violent or inciting violence against you.
simply saying things you don't like hearing
That's a disingenuous way of portraying hate speech. Even if you're in the "tolerate hate speech" crowd there's no reason to trivialize someone else's position.
You're under no obligation to agree with popper. There's no need to turn his position into a different one so you can agree with him. We don't need two Rawls.