No, he's not immune to blunt force (or so we can assume because spidey tries to crush him), but even though he isn't, after doomsday kills Freak, freak will be resistant to it when he comes out of his cocoon in a few days. And I don't believe that Doomsday would be able to break Freak's cocoon, because the cocoon is a very strong acid, which would completely disintegrate the part of Doomsday's body that touches it, and so no part of doomsday will be able to create a resistance to the acid, because any part of him that touches the cocoon will be completely dissolved, including the DNA, not allowing regeneration because there will no longer be any molecule left to replicate (this is speculation though, because if doomsday has already been exposed to acid and developed a resistance to it, then it won't matter, and if doomsday's regeneration ability doesn't work in the way I'm thinking it does, he'll just get immunity. I'm not very familiar with doomsday, so I'm just going with what I think would happen from my current knowledge).
"I guess we'll have to ask the OP, but I was always under the impression that defeating someone once was enough in a battle thread unless otherwise specified."Touché, so yes, that means that it's an easy win for doomsday.
And in my opinion the point is really moot as to who would win if they both had nothing to do but try to kill each other over and over again because eventually they'd just be sitting there punching each other for eternity (throwing Freak's cocoon into space might not work, because Freak's cocoon may keep Freak alive in space, but there's no way to tell).
There's no question, if they were set upon each other and told not to stop until the other is dead for good, the battle would rage on forever unless one of them somehow makes it impossible for the other to revive.