BRNR,
Just wanted to say again that I'm in a very similar sitch and I really feel for what you are going through. Just one small for instance:

My H was ordered by the judge during settlement to lodge his tax returns so that we could ascertain what his income was.

I thought I had finally gotten somewhere after years of trying to make him produce some relevant info.

XH simply ignored the judge. I imagined he would have been in contempt or something... but nothing happened.

In the end he simply withdrew from the process rather than lodge his tax returns. I was left trying to run an uncontested case - which I thought would be good for me, but it turned out to be harder and more expensive to argue than a normal case which is argued by 2 spouses.
XH had won again.

It's so weird, I agree with you that the caring dad and loving husband they once were shows no skerrick of resemblance to the devious obligation-voider that we have been left with in mlc.