Mazzo

For prevent blobs at extruder change just enable prime tower in dual extrusion settings. You can also with nozzle switch extra prime amount in dual extrusion setting use this with negative number to make less plastic come out after the extruder change

For start with correct extruder you have do this: from the settings of the 3d printer just copy the original start and end gcode from kisslicer, and at the end of the start gcode just add T0 or T1 or T2 depending on the extruder that has to start printing. For example if the print starts with a raft with HIPS on extruder 3 add T2 at the end of the start gcode. I have a 3ntr printer with 3 extruders and everything works fine with cura.