First take a good look at

http://www.welshdragoncomputing.ca/eqmod/doku.php?id=ways_of_controlling_slew_rate

and

http://www.welshdragoncomputing.ca/eqmod/doku.php?id=slewing_presets


The slew rate can be changed in two basic ways.

1. By directly nudging the rate sliders on-screen or by assigning gamepad buttons increment/decrement the rate. The rate can vary from 0.1 to 0.9x sidereal in increments of 0.1 and 1-800xsidreal in increments of 1.

2. By selecting a rate preset via the onscreen dropdown, by assigning buttons directly to specific rate presets or by assigning two gamepad buttons to increment/decrement the current rate preset.

In making the changes in the ini file you are setting up the rate presets.