Hi Seamaster
If the OAA could only play Yamaha styles then I would agree with you, however Yamaha style play is merely a convenience, (Most conversion software has difficulty with the latest Yamaha styles, so Wersi has just provided a solution for those that want it) and as NO Yamaha styles are even provided, this rather blows your theory out of the water.
BTW The OAA can directly read the following formats:
stw. The native OAA format
sty. The Yamaha format
sto. The old OAS format
Styles in stw format are continually provided during the various free updates, (An additional 14 Christmas styles have recently been uploaded to the Wersi site)
I would also be interested where you got the information that the OAA needed Yamaha styles to work, (I have certainly never said that) as there is no literature, forums, (Including SZ) or anywhere else that says this.
Regards
Bill