I think the answer to my question is probably no, but I’ll ask anyway. I have Roon core on my Dell laptop and Nucleus. I will now use the Dell just for travel. Other than doing a backup from Nucleus and restore to Dell, is there any other way to keep them in total sync? Probably not, I suppose. Thanks.
Backup and Restore, as you guessed. There is no cloud sync.
PS. I do believe cloud syncing between 2 cores (used 1 at a time) has been a Feature Request since 2016. If you can find it, add your voice!