We are using S/4HANA Cloud.
For sales orders with billing plan item category (CTAD), we don't want the sales order creator to remove the billing block from the billing plan tab. It should be removed only by authorized people. Is there a solution to mitigate the business risks on this scenario?
Please have a try of the Cloud BAdI "Sales Document Check Before Save". For example, if the user equals to the authorized one, then the sales order can be saved. Otherwise, the "save" action will be blocked. Please reach out to your local developer or consultant for the detailed logic to be written in the BAdI.
Check more details here: Help Portal - Business Add-Ins (BAdIs) for Sales Documents