It almost doesn't even matter because outside of musical gear, OSC is becoming the established standard to control everything from DMX lighting to VJ software to OF/Cinder interactive installs to some more performance oriented software like Ableton Live (via LiveOSC).
I've written software MIDI sequencers (all the way back in the early 90's even) and you'll never be able to convince me MIDI is better than OSC.
(disclaimer: I develop an OSC-based sequencer, https://ossia.io)
That said, I only assumed as much because I don't know of any OSC client software that uses anything other than IP networks to facilitate device to device communication. I googled for serial OSC software and found some nonetheless. Does your software support OSC over serial?
not yet, sadly ! I've got a lib for that however : https://github.com/jcelerier/oscour