Note, that you can also transform your PSR into a bigger one with vArranger, with 5 instruments layers for right hand, and 3 for left hand.
You can directly load your PSR styles in vArranger, and play with the OTS too
You can import the list of instruments of your PSR and have access to all of them from vArranger
The Yamaha DSP FX are well played, but a new version will let you to edit them easily too.