The Orb will work with the OS. I have a Future Retro 777 that I use as a cv/gate sequencer for my sh-101. I believe the orb is basically an updated/redesigned Mobius, where the Mobius is a 777 without the synthesizer. I am sort of checking it out the orb myself.
Future Retro sequencers are similar to the old Roland sequencers. I think of it as a cross between a TR-x0x and a TB-303 sequencer. After all, the 777 was marketed as a TB-303 clone, although it doesn’t quite sound the same and goes far beyond the TB-303.