I think an interval would be a good idea. In combination …

I think an interval would be a good idea.
In combination with a flag, that the post is from a blocked person, which makes it kinda interesting.
For me personally a "flagged blocked post" would trigger my attention due to the curiousity if it was blocked on purpose or not.
I then would read the post.
If it is just ad hominens I would ignore it and maybe me and other people could even add our vote to an even longer "blocking interval".
But if it is quality post it would draw some attention and you couldn't get rid of unpopular opinions that easily.