Modifying Line Items after Reaching Terminal Status

Hello all,

Is there any reason or design consideration that forbids users from modifying the line items after a record reaches its terminal status? While the Upper Form contents can be modified by giving an edit permission, why can't the line items? I've tried changing the form that is used in the last step of the workflow to an Action Form, but still not able to change anything after the record reaches terminal status.

I have lots of cases when we had to create new records after realizing that the previously approved records have incorrect line items. What makes things worse is that the record has already been used as reference by another BP. We have no other choice but to recreate another record for that 2nd BP that picks the new created record in the 1st BP. If only the line items can be modified, we wouldn't have such "