Hi Steve,
It is possible to move the folder from v12 to v13. To do this, please make sure to have the program completely closed.
Open a file explorer and go to > C:\ProgramData\2020\Design\12
In this location, you want to copy the folder named ‘Custom Materials’.
Once you copy this folder, then you want to paste it in > C:\ProgramData\2020\Design\13
Once this is completed, you can close the folders and go back into the version 13 to find all of your user textures right where they should be!
Regards,
Kris