On the face of it, you have a court decree. The "easiest" thing to do is to follow it.
Title: If the title to the property is still in some form of joint ownership, you may have trouble getting ex to sign a deed transferring to a new owner, so thatâ€™s at least a minor consideration. Forcing him may cost legal dollars and you don't need that expense. If thatâ€™s the case, acceding to his wishes may be the thing to do, from a practical point of view.
While you seem to be content to help ex with his finances, we really don't know why. That's a social issue that may well weigh more heavily than practical or legal decrees. That part is just too tough for anyone to call, excepting the two of you.
On the other hand, depending on how much support you feel you "owe" your ex, be aware that ten years down the road you may question why you added a completely side issue of an IRA to the already complex procedure of transferring a property after a divorce.
Another point, if you can sell the property for a figure high enough to pay off the mortgage, ex pays the house off at closing, just like everyone else does. No IRA draw down, no expenditure of existing funds.
From yet another perspective, I'm not sure what rolling a debt into an IRA means. Have you had a good IRA specialist (CPA or financial advisor or retirement attorney) look over this deal? Ex may be way off base here. Frankly, I've never heard of this kind of deal and yes, I have an IRA and have reasonable financial advice.
Bottom line. You had a marriage. You and your ex ended it in some fashion. You have certain rights proceeding from the divorce decree. My advice is to get competent advisors in ALL the needed fields before you change a thing. Remember, the court has come up with a deal and a deal's a deal.
What you get in a "redeal" fandango may not be to your benefit.