I also prefer to avoid Streambyter where possible, and you don't need it in this case.
Things are more reliable when super controls drive sub controls. Reverse drive will work sometimes - as your current architecture shows, using the sub buttons to activate the supercontrol to send the message.
Easiest thing is to flip your layout above, and add a new top level supercontrol.
- New knob, midi receive on, receives the pad commands and groups the 1-16 buttons, options as super: send on only, midi 0 - 127
- 1-16 buttons, midi receive off, midi values are 0, 8, 17...127 (alternate adding 8 and 9 to the prior value), options as super: send on only
- The knob that sends the midi out control arp speed is a subcontrol of the radio buttons.
The pad midi values need to match the button values (0, 8, 17, 25...127). You can use different range of midi values on the pad, but that will require two additional controls - one to receive the midi, then one to rescale to full range (0-127). (To drive a subcontrol full range requires a midi value of 127. You can learn more on this in the MDP2 Masters Course Layout).