Thanks for understanding.
Regarding MIDI implementation, it sounds like you're talking about actually using MIDI to make the change. That's cool and I hadn't even considered such a thing. I would expect that sysex or nrpn are too esoteric, but that MIDI note and CC values would be a better choice as they're something that nearly every controller can output.
But then again, why not just use the Grid/Arc to make the changes? I say this not really understanding what's involved in coding such a thing.
As for the reason why an offset for controllers like the OP-1 is preferred, I'll explain my use case. I like to use the OP-1's internal sounds with my modular, primarily patched into modules like Clouds and Morphagene. But I also like to patch the OP-1 into a USB to CV converter to be able to control modules in my case either with the keyboard, or using something like the OP-1's Tombola 'sequencer'. Because the OP-1 outputs MIDI all the time, I'm able to mix together the sound produced by the OP-1 along with the sound produced by the modular (controlled via MIDI) and it's just easiest if the octaves match up. Of course, I could always use some sort of precision adder to bring the CV up to match that of the OP-1 audio out, but as it often is with modular, the fewer modules/less hp one needs for a task, the better.