I think we've gotten way far off track. Basically, record the Pianoteq with your DAW, 32-bit floating, 48kHz, you'll have top quality sound file for FCP to work with. Routing directly to FCP won't help, because it'll just record at 16-bit, 48kHz video standard. Your DAW or music app can probably record at a higher quality. So routing directly to FCP will actually hurt your sound, defeat what you want to do. So, you're not losing anything, you're gaining. Do NOT go directly to FCP if you want the BEST quality out of a sampled instrument, use your DAW!