There’s no such thing as a 32 channel SMF. By definition, each MIDI port can only send 16 channels. While it is possible to store multiple concurrent 16 channel tracks in a DAW (and route each to a separate MIDI port) you cannot save this as an SMF, only as the save format of the DAW. If you tried to, the DAW would ‘flatten’ the file down to 16 channels, mixing together the Ch1 information for both ports to one track.
MIDI 1.0 was invented before multi port interfaces, and no one thought that we would need a file format that supported more than 16 channels!
However, MIDI 2.0 is a totally new kettle of fish, but to my knowledge, no new SMF format has been standardized, and certainly no legacy modules will be able to understand it.
I think the only way QMIDI may be able to pull this off using MIDI 1.0 would be the ability to play two ‘normal’ SMF’s at the same time sent to two different ports.