To which form of Annotation can I convert a custom watermark so that it can be applied following PDF digital signature?

We have been traditionally using the watermark feature to mark up PDFs following electronic approval in a PLM tool so that desiring customers can receive a distributed electronic copy and verify the agreed upon reviewers/approvers have been utilized. The approval stamp includes Change Order, Date of Effectivity, and the list of approvers and their respective roles. There are over 40 variations of Routes used in the PLM for which over 40 custom approval stamp variations have been created in PDF with form-enabled fields to improve accuracy for listing approver names.

We are now starting to have digitally approved documents being submitted for final electronic approval instead of wet signature approvals on some of these documents. An example is a QA signature on a specification that is then submitted through the full electronic approval process. We cannot apply the PDF watermark feature post approval as this is not considered an annotation that can be allowed following digital signature (at least for Adobe Standard X which we are currently using).

I would appreciate some assistance with resolving this dilemma. I am willing to explore various annotation options and pushing the digital signatories to utilize the option to allow for annotations post-approval.