I personally thing it's going to be a major pain to have to load patches with another utility however simple it is to use. Is anyone planning to add the two lousy calls to windows to load the patches and drums that is needed to their sequencers?
It is not a major change to add this stuff. A bit in the capabilities structure tells you that the driver supports caching patches, you build an array of words ( one bit for each midi channel) on word for each patch and pass it to the driver by calling midiOutCachePatches. A similar call is done for the percussion. An example of this is in KBMIDI and DRUMS both at archive.epas.utoronto.ca.
I am eagerly awaiting a sequencer which supports this.