Generally, the signer is directly investigated. Although you didn't design it, your last signature means that this drawing is approved by you and you are the person in charge.

As for the drawings you don't know, the company will take you to sign them: first, if the company uses your private seal, you will be responsible. You didn't take care of your important objects, and the fact that you didn't participate in the design can't be proved, unless others automatically admit that you want to find you; Second, it doesn't matter if the company takes you to initiall all the notes. The notes are not yours. When something goes wrong, it's none of your business to apply for notes authentication. If you can find a designer, you will be responsible for it, not the company.