I have caught up on your thread. You H is on Santa's naughty list for sure. And not the fun naughty list either.
I am sorry that he is putting you through this now. He is playing on your emotions. He is expecting WR to give in. Honey, you are going to show him that he is dead wrong.
If you think you will be OK to meet with him, I think you should. Agree to nothing and make it clear to him that you are there to listen to his proposal and then will consider what he has said. It will be tough if he pressures you. Have you got a phrase or a song that makes you feel strong? Play that in your head if you meet with him. You are there to listen, not negotiate.
Another suggestion would be to ask him to write down his proposal and you can meet to discuss it. Again, only to discuss it.
After that meeting - whether or not he has his proposal written down - give your lawyer a shout to discuss what he has said. Ultimately, I would have your lawyer draw up any papers that need to be signed and/or filed. There will be some Provincial requirements that your lawyer will be aware of.
The good thing about the meeting with just the two of you is that it will allow you to gauge whether or not you require your lawyer to do the negotiating for you. Keep your court dates. If nothing else, the Court will endorse the record that you have attended. The Court will never be angry if there are delays to work things out or to attempt to work things out. The Court is not too fond of cancellations. The Court also hates dead beat dads and this is a chance to get that on the record as well.
WR whatever you decide, I know that you will do the right thing for you and your kids.