"Payment Terms" Modifier

Hello,

Customer wants to create a Payment Terms modifier for some items to reduce stock.

I tested this by setting up a modifier:
- Type : Promotion
- Modifier Type : Term Substitution
- Terms Attribute: Payment Terms
- Terms Value: The new payment term.

That works ok, BUT:

When the modifier is triggered for an item that is qualified & afterwards the Item on the order is changed back to another item that is not qualified for the Payment term modifier then the payment term should change back to the default payment term. It seems that this is not happening. The payment terms modifier remains on the Order and