And I know no reason why the Inherited Obligations family can't sit down together and negotiate what the inherited obligations are to be. That is, except at the most extreme end of the continuum, I know no reason why the obligations in an IO family have to be identical for every such family, any more than the commitments in an NC family have to be identical for every such family.
Example ... a small example, but adequate to demonstrate the point: Christmas presents.
Christmas at my house has in the past often meant a very large group of people and very large piles of presents, the opening of which was a public event observed by one and all. For some of my adult children a point was reached when the standard obligation -- "When you give me a Christmas present I have to give you a Christmas present" -- became a burden that threatened to make Christmas an occasion for dread instead of for rejoicing. This was complicated by the fact that some of the family-members-in-law came from families where the standard inherited obligation went like this: "When you give me a Christmas present I have to give you a Christmas present that's equally expensive."
My adult children (my chadults) therefore negotiated an Obligation Modification: that none of the chadults would give each other presents during the big family Christmas bash at my house. Presents would be given to the elders there; presents would be given to the children there; but the middle generation would not participate in the gift exchange.
This solved the problem, turned the annual celebration back into a celebration, and in no way weakened the network of obligations. Furthermore, there is a legitimate sense in which refraining-from-giving-a-gift is a gift -- a gift of release from public competition, a gift of release from public embarassment, and a gift of freedom to just have a good time.