Is there really an essential difference, though? Hate speech is just a particular type of marketing, which is mostly just ideas presented dishonestly in some way (selective, biased, whatever). What is being marketed is particularly repulsive, but that also makes it particularly easy to argue against.

In cases where one is supplying a venue that otherwise would tend to prevent challenges, it might be reasonable to require some time for a dissenting (e.g. more honest) point of view.

It's not really a marketplace of ideas if one idea is in a big display on the way in, and at the checkout counter in case you missed it the first time; and the other idea is hidden off in some dark back corner, too high for most people to reach.

But the thing about hate speech is that if you are allowed to speak against it, and it's not inducing imminent activity, it tends to be pretty transparently awful and therefore is easy to speak against. And if it is a legitimate concern that the speech will induce danger, well, then you get them on incitement to violence. I don't think you really need a separate category.

There are lots of tricky corner cases, but I don't think they're tricky because they're hate speech specifically.