@dillingerwa
Look out. You're correct about the fact that your scenario involves an "amendment or modification", but note that the Reg states the requirement in the conjunctive (i.e., "and").
So, the transfer must be pursuant to a divorce or separation instrument (including a modification or amendment) and the transfer must occur within 6 years after the date on which the marriage ceases. Otherwise, there is a presumption that the transfer is not related to the cessation of the marriage.
However, that presumption is rebuttable which is primarily the reason I suggested you consult with a local tax professional or legal counsel.
