so, I have updated the skywatcher.cpp as advised by you:
Line 415: minperiods[Axis1] = 12; //6;
Line 416: minperiods[Axis2] = 12; //6;
Recompiled and installed the driver. The change is being used as evidenced by the log file entry:
DEBUG 0.287078 sec : InquireBoardVersion(): MountCode = 35, MCVersion = 30e23, setting minperiods Axis1=12 Axis2=12
Unfortunately, there is no noticeable change in the goto slew speed, i.e. still at its maximum (800x as shown by Ekos).
Attached the log files with the debug level active.