I don't care what type/brand of switch you use, the motor should always be before any type of switch, the starting DC current load on a motor will eventually blow out the input/output on any switch.

Even some receivers can't handle the starting load of some motors, the starting DC current load (amps or milliamps) will be even higher on a 13 volt transponder. (all vertical transponders)(the lower the voltage the higher the current)

It should always be Receiver-Motor-switch-LNB.

Also a good idea is to use coax with a pure copper core, some coax has a copper coated steel center conductor, this type will have a higher DC voltage drop at the far end.

To test the type of center conductor use a magnet on the center conductor, if it sticks it's steel.