That's the thing: if you have VST or ReWire support, you don't need to implement any of that. That's now something someone can use a VST/ReWire bridge for, taking all that work off your plate. "If you need MIDI sequencing, or multi-pattern input, or randomized pattern generation, just connect your DAW of choice as input".

(And of course, "and if you then want to consume the result in another DAW, you can". Chaining up multiple DAWs because they're all good at different things is one of the more fun things to do ;)