copy the FedEx and UPS livery over from my MSFS2020 install worked. So the folder structure for 2024 should be the same as 2020, but it's not.
2020 on the left and 2024 on the right
The 2020 install and 2024 install go in completely different sets of layers.
Again, drag-and-drop from 2020 into 2024 is working.