Yes, this is true about Technics or other non ".sty" styles. You can still listen to the many different manufacturers styles (including Technics, Roland , Solton, Korg and of course all of the modern Yamahas) ) that have been converted to Yamaha ".sty" files. There is a wonderful E / yahoo groups site which has literally thousands of converted styles. This site as well as several other style sites are listed on Jorgen Sorenson's outstanding PSR740 website. The URL is http://home7.inet.tele.dk/js/musik/740pages/link740.htm
Good Luck
Al