Restrict Bill Line Amount Adjustment Action for Active Subscriptions

Summary:

We would like to allow the Bill Line Amount Adjustment Action only for Subscriptions that are in Draft status or Under Amendment status. If the susbcription is Active, user needs to do an amendment before they can change the amount of the Bill Lines.

Content (please ensure you mask any confidential information):

Under Billing Summary tab of the product or covered Level Asset (it is extended warranty product), there is a column "Actions" which will allow user to Adjust Amount of each Bill Lines. This action can be performed on Active Subscription as well. We would like to restrict this. Any option to enable this option only for subscriptions that are in Draft or Under Amendment status?