@neuron
Read here, Perhaps it helps. It’s a very complicated thing.
I would prefer to install RapidWeaver on the second computer, and then to reinstall all themes and plugins on the new location.
That gives a lot of work, but everything is correct.
Or…
This is the somewhat simpler way.
When you copy this file/that folder you should have all important things on the new computer.
com.realmacsoftware.rapidweaver6
/Users/your name/Library/Containers/com.realmacsoftware.rapidweaver6
Maybe you need retype this or that password.