Hi Dave
I am in touch with a guy who sorted out the sysex codes for all of the Tyros 3 styles - trouble is that they don't seem to go to the correct styles - or I have misunderstood him
The sysex messages only alter things inside a style, they won't change a style for you (if that's what you meant)
I think I have the basic idea on sysex messages now and can probably formulate a message for you for any parameter. I've just been playing about on the Motif putting a fade into the end of a song using sysex rather than altering velocities In this case you have to 'create continuous data' identifying the the tracks and measures etc that you want the fade over, choose sysex for the event type , the range of the data (127-0), the increments (not below 60 ticks) and the fade curve. Press [ENTER] and hey presto the fade is there. One thing you have to do is then bring the volumes back to full or next time you play the song you won't hear anything because the last volume was zero. You have to put the following message in
FO 7F 7F 04 01 00 7F F7 at the end or [reset all controls] at the beginning.
All the values are in the data list, it's just a case of deciphering them. There's a good days reading there!

Cheers
Spike