Just wanted to add, the threat on custody is most likely the L's suggestion of a negotiating chip. You'll be so anxious to get more custody, you'll give away on the financial side. It is a very crass and callous thing to use your kids as a kind of negotiating black mail.
You need to do what you can w/ your L to make it so there is no way the courts would award anything like her custody arrangement, then you can not be black mailed. You just laugh and say that is a non-starter, so let's just dispense with the farce: it will be joint custody. Now let's start negotiating on the financial side.
So, first stop is the L's to figure out how to take that bargaining chip back of the table whether she likes it or not. She may agree to mediation at that point, once she sees that this is going to be a messy give and take with a hostile party whose pissed that she pulled this crap.
Then you need to decide if you really want someone who would agree to use their kids this way.
Me: 50 W:43 S6, S3 M: 12 yrs. T: 17 M is bad & Not happy Bomb Mar '14 S 5 Feb '15 D Bomb 13 Apr '15 (but "no hurry") DB Coach May '15 Wants proceed on D Aug '15 Starting 1-on-1 negotiations Sept '15