Hi all, im not sure if this is a bug or if its just one of the compromises the engine has to make in order to render the sound through the Sketch sequencer, but i noticed that if i have the Sketch sequencer enabled, simply enabled, and then i navigate to say the FM Cermon synth preset, the sound of that synth is quite different, almost as if its compressed or overtones are removed. Try it:
Go to the Sketch sequencer and make sure it is enabled, then go to the Synth screen and select the FM Cermon. now simply play a few notes of the synth and then toggle the sequencer off and compare the sound of the same few notes. i hear a pretty distinct difference in the tone/texture of the notes.