Not sure if it's the case in all Daytonas, but the DSB on mine comes with an extra board on top. If I connect one output, the sfx/speech comes from it, and the second output is totally dedicated to music.
God, I wish I was a helluva programmer, to implement the function of generating a memory map where the sfx roms where read from the microsd, and the DSB understood the SFX calls from the main pcb, to play the right sound effect, at the same time it plays the uncompressed wave files I've uploaded to the microsd. The files sound soooo good, just listen to the attached sample.
In the meantime, I'm seriously thinking in use both PCBs in parallel. Use the DSB replacement for music and the OEM for sfx. My only concern is power consumption and any problem by having the MIDI output from the PCB connected to 2 pcbs at once.