A cloning software will make your life easier. Even for incremental backing up.
When you start using the ExFat as your main drive it will increase in size, then you may want to back up that drive to your old NTFS, instead of copying everything over the cloning software will just update the NTFS with recent changes saving you time.
I’m a Mac user and I use carbon copy cloner. I’m sure there are equivalent ones for Windows as well.
What size is the NTFS drive?
One of the the benefits of using ExFat with Engine prime as your main collection drive is that you can equally plug that complete collection drive to any of the prime players and it will read your Engine prime crates etc easily.
So if you have a small set, export a crate to small thumb drive, but if you have a wedding plug in the entire collection drive.