Peter,
The guide rate you selected (0.8x) has very coarse steps in RA. Selecting 0.5x or slower would result in much smaller steps. However step size is constant in Dec.
The 0.11 arcsec step size with the new gearbox will allow for a smaller minimum guide move if your seeing is good enough and you can somehow manage Dec backlash to take advantage of the smaller step size. In other words, the limiting factor should not be the step sizes anymore, but the other factors impacting guiding will still be there, which I believe is your objective in implementing this mod.
Eric
