Hi metalb00b00
Ok, lets go further then, with some precisions
HUI is tweaked midi (as you show) it act more or less like RPN/NRPN, so its a 14 bit message
At 89MotioN the software MIOS send/receive 14bit PB midi data, AD and DA for analog motor driver are 12bit
With my DAW which is Digital Performer, using MCU actually send/receive full range pitchbend value (RPN 14bit)
checked with 30 min automation ramp, it increment whithin 1 in the 14384 steps)
Now in HUI mode my DAW only send MSB 0-127(7bit) steps and LSB is 4 steps (in 7bit format...) value 0-31-63-95 only
it end with 128x4 possible value 512steps, 9 bit
Here is where come my math
BUT if other DAW handle better or full(14bit) definition by sending/receiving HUI type fader data you will have better than 512 steps
I don't have Protools, I can't test this

Best
Zam