After playing around in a test project I'm pretty sure option 1 is right. There's no need for the previous combined id to be included because it doesn't inherit anything from that dataset. Happy to be corrected though
Hello @<1604647689662763008:profile|PerfectSwan93> , I tend to agree with you , option one is the best given your use-case. If you keep the same name and project it will result in a version bump on the combined dataset, but it will not point to the previous combined dataset as a parent.