Looks like an interesting thing, I may try to take some from here and mix up with my libADLMIDI (and libOPNMIDI) to finally drop the rest of Bisqwit's code that is GPL. The half is already mine, I had to replace a lot of it. By the way, I checked the code and it mentions that volume models were not supported here. It's the very important feature I made to give the almost same sounding of every bank as they sounded in their original midi drivers (You can review some
here, NukeYKT also helped me to develop the AIL, HMI, and DMX volume models being more accurate). Together with volume models, I developed the different frequency formula to get the same as the original midi driver, which is very important for drums, they were very sensitive to the frequency formula!
Devinacker's MIDI sequencer needs improvement as it doesn't support loop tags which is also an important feature I do have. By the way, I had to post my MIDI sequencer here
https://github.com/Wohlstand/BW_Midi_Sequencer separately, It's internal libADLMIDI and libOPNMIDI's MIDI sequencer published as a general-purpose header-only library, I already use it with FluidLite at my MixerX fork and I do use it with Windows Native MIDI as an alternative sequencer that supports loop tags and other formats than just MIDI. However, MUS and XMI code at me is LGPL-licensed copypasta from the WildMidi, I must replace that with Devinacker's to resolve this license problem, however, I kept an ability to disable MUS and XMI to use the MID license.