Sorry to keep pestering you.

Is there a way to change the FluidSynth option synth.device-id in the Qsynth UI?
The Settings tab in the setup window seems to only allow me to view the settings.
I have looked in the registry but can't seem to find it.

The default value of synth.device-id is 0.
However, the default device-id for classic GS and XG devices was 16 (0x10 in hexadecimal).
It has been confirmed that when classic SMF (.mid) is replayed in Qsynth, the intended GS and XG reset behavior is not performed due to the device-id difference.
See also.FluidSynth/fluidsynth/issues/1323

It would be useful if synth.device-id could be variable in order to get closer to the behavior of classic GS and XG devices.