As mentioned before, a RK-002 is something like 50€ and you can do whatever you want with it, if you’re willing to learn the (very simple) SDK.
Given that the midi control over the arranger like you would like it isn’t implemented in the OT and will never be, it’s already great that actually working solutiuons have been suggested!
And remember that eliminating completely even the tinyest laptop from your rig is a personal choice that has consequences you now need to circumvent.
Alright folks,
The midi controller Morningstar MC8 is now capable of sending SPP.
After I bought the pedal, I emailed their tech support and asked whether there would be an addition of SPP in the near future.
Then I received an email within 24 hours from the chief engineer (possibly the owner) James Toh
stating that he had included the SPP in the beta update.
Here is how to roll
Update the firmware
Beta Firmware v3.7.0 (scroll down the page)
https://github.com/Morningstar-Engineering/MC8-MIDI-Controller/releases/
Use this online editor v.1.0.11 (SPP section will only show up on this editor because its beta, not the desktop version)
https://editor-mkii-staging.morningstar.io
This pedal is absolutely a winner.
Is there a clear guide to midi mapping and clever tips and tricks somewhere for Octatrack?
The manual does my head in 
I hope this gets added to the MC6!
Anyhow, it’s sort of moot now but I was going to recommend getting an Axoloti and an acrylic case rather than the MIDI solutions box for MIDI processing. The MIDI solutions stuff works well but for barely over half the price (and some effort) an Axoloti would do so much more.
Thanks for the tip, mate.
I think, I am sorted now.
I am sure he will honour your request, if MC6 or MC8 differ on the firmware.
Give them a shout through their website!