multiple certificates 1 pem

Hy, my server certifcate ends in some months, so i am thinking about to create a new certifcate on the server and combine the old and the new public key into one pem file.

So i can deploy this new pem file with ocs-Inventory without beeing reliant on active directory deployment.

Does anybody know this could work ? (i will use the old server key until all clients have the new combined client certifcate)

Kind regards