GM, I continue to be amazed at the similarity that is exhibited by mlc-ers.
My XH said EXACTLY the same about mediation. He was all in favour of going - but as the time drew near, he stipulated that i had to agree (in writing, via email, beforehand) that I was willing to settle on his terms.
He saw it as simply an opportunity to have the mediator get me to sign off on his (completely unsubstantiated by financial documentation) version of what i owed him.
It was bizarre. Like you, i tried to point out that if i did this, there would be nothing to mediate... but I got nowhere.
Eventually, he agreed to attend the session, but after 20 mins, it devolved into an argument, after he kept maintaining his point that we were there to agree to his terms, or nothing. Finally, he shouted that it was all a complete waste of time and he stormed out.
The mediator had to pick his jaw from the ground and was left commiserating with me in the meeting room.
What I'll never understand is how these mlc-ers can think (and verbalise) so alike, in such crack-pot ways, about a range of different things.