Hi Graham,
You can also try to quantize R1,R2,R3 voices on your keyboard and test the results.
First you have to save your original recording as a midi song(midi file)
We always save our very first recording, so if we make a mistake in the process it won't give as any troubles and can always go back.
Then you have to enter to Song Creator.
Search for the tab called "CHANNEL".
You can see the quantize option there and select it.
Select channel 1 and press Execute(it is your Right 1 voices)
Select channel 3 and press Execute(it is your Right 2 voices, I think on Tyros is the same as on my psr)
Select channel 2 and press Execute(it is your Right 3 voices I think on Tyros is the same as om psr)
Afterwards go to SETUP and press again Execute.
Now you can save the midi song with a NEW name (so not to loose your original recording).
Listen to the new midi.If it is something that you don't like,select again your original recording.
Now in the Quantize option you can see some 8th,16th etc notes in box called SIZE.
Try a new note to quantize your 3 voices e.g a 32th note.
The keyboard will quantize your playing slightly differently and maybe is fine with you.
Before saving your quantized midi song,you can press play every time you change the size of the notes while pressing "execute" to hear the results so you can cancel them and try something else without having to exit the Song Creator.