When drawing a long line in the Key Editor controller lane over perhaps 16 bars, the result is limited to the 128 steps of the MIDI spec. Is there a workaround to increase this number? Sometimes the stepping is clearly audible. I suspect this is a MIDI limitation we have to accept.
If you mean the number of drawn controllers, this is based on the Grid setup.
If you mean the range of the controllers (0-127), then you can’t increase this. It’s specified like this in the MIDI specification since 1983.