PDFsharp & MigraDoc Foundation

I'm using the specific PR that has Signatures added to
from what I read, adding a second signature invalidates the first one saying SigDict /Contents illegal data since we are creating a new document, and as a solution for that is to tell pdf that this is an increment of the old one and not a new version

When I use the append filemode I get the following error Unable seek backward to overwrite data that previously existed in a file opened in Append mode.

up, any news for incremental updates?