Sign PDF asynchronous using PDFBox

With reference to this question Sign pdf asynchronously using digest. I am now doing exactly the same thing. I am trying to explore is there any new method to "save" the intermediate PDF object to database after getting the hash, and then load it from database again after I got the signed hash from somewhere, and then continue the PDF signing process.

(I notice that there is a similar operation using itext, which called deferred signing https://kb.itextpdf.com/home/it7kb/examples/digital-signatures-chapter-4, but I can’t find similar reference for PDFBox.)