I am in the last few days of my free trial using my MAC as my base and went ahead and ordered a nucleus+ which raises the question, is it best to just transfer somehow from the MAC account or should I just let the free trial expire and then do a new account and fresh set up on the nucleus
For continuity, extend the subscription on your current Roon account and continue using the Mac.
Then when you get the Nucleus setup, perform a Roon database backup from the Mac, and restore than onto the Nucleus.
Check out the Roon Knowledge Base - Nucleus Migration Guide for detailed information.
thank you for such prompt help.