Using Preview with an old PDFkit With Mojave, I use to open multiple pdf at once with the old Preview9.0.app  (version of Sierra) 

It doesn't work anymore with Catalina because of a conflict between Preview9.0.app and the new PDFkit framework. 

Is there any way to embed the old PDFkit framework in Preview9.0.app ? Or redirect PDFkit calls to the old one ?
I'm sure it was possible ! Cormiertyshawn895 dit it ! Thanks to him ! https://github.com/cormiertyshawn895/Retroactive/issues/1