Multiple serial keys

Hey, so I have a strange question. I’ll just give the backstory here.

So, I have an EA Play (no longer “origin”) copy of Dead Space 2. Runs great (with the Windows compatibility administer). I notice it has a serial key in the “details” tab, which is the key it assigned to me when I downloaded the game from EA Play.

Now, the Collector’s Edition content was never made available after release in any other capacity by EA. I recently found a sealed copy for a decent price, and I would like to use that CE serial key. How would that work? I’ve read that having a registered copy of DS2 unlocks a digital version on EA Play (formally Origin), but what if I technically already have a standard version on there? The CE content is specifically tied to the serial key itself. Is there a way to switch or add the CE serial key to that account? Would it just add as a separate game? How would this work?

Thank you for your time