At any time after confirmation and before "substantial consummation" of a plan, the proponent of a plan may modify the plan if the modified plan would meet certain Bankruptcy Code requirements. 11 U.S.C. § 1127(b). This should be distinguished from preconfirmation modification of the plan. A modified postconfirmation plan does not automatically become the plan. A modified postconfirmation plan in a chapter 11 case becomes the plan only "if circumstances warrant such modification" and the court, after notice and hearing, confirms the plan as modified. If the debtor is an individual, the plan may be modified postconfirmation upon the request of the debtor, the trustee, the U.S. trustee, or the holder of an allowed unsecured claim to make adjustments to payments due under the plan. 11 U.S.C. § 1127(e).