Good question about the actual opening of the packs...ideally that would be purely a cosmetic thing and not require any type of logging or RC, but I need to think about that more.

I thought you might ask about reward cards...those don't come in packs so there's no issue there. The generation algorithm for those is published here: https://steemmonsters.com/?verify_rewards=1 you should be able to see the JS code in the page source.