I've also been playing around and managed to get the Wii 4&5 songs into the game!
With regards to the no song preview issue, if you open your custom NUS3BANK in a hex editor, there are two instances where you can overwrite the songID (assuming you used an existing NUS3BANK song as a template). This fixed the issue for me.
I'll have to have a bash at loading the PS4 songs
With regards to the no song preview issue, if you open your custom NUS3BANK in a hex editor, there are two instances where you can overwrite the songID (assuming you used an existing NUS3BANK song as a template). This fixed the issue for me.
I'll have to have a bash at loading the PS4 songs