AP/AR Credit memos should have the option to cancel/reverse, reopening the original invoice.

Things happen, and the reversing of the AP credit memo can become necessary. You may say, just re-create the original invoice. Well, sometimes there's sales orders and other linkages to keep. The accounting manager role/super user, should have at least some more power over deleting options.

Reversing and linking of certain transactions has some value when it comes to keeping the GL clean.