Garmin Rally RS200 vs Ultegra PD-R8000 stack height

Pedal bodies do not have the same thickness. Thus, swapping pedals may change the effective height of your saddle. Should you lower ⬇️ or raise ⬆️ your saddle when installing Garmin RS200 pedals over Ultegra PD-R8000?

Let's have a look at some manufacturer data:

So when installing garmin rally RS200, one should lower its saddle by 3.6mm. Right?

Garmin pedal body really seems thicker than the ultegra one, but garmin reports a smaller stack height. How can this be possible?

For some manufacturer, stack height refers to the position of the pedal platform relative to the center of the pedal axle. For others, the position of the top of the cleat (the position of the shoe) relative to the center of the pedal axle. This is why the numbers above seem odd.

I have measured the position of the pedal axle relative to the platform for the two kinds of pedals above. Garmin platform is 2mm higher than Ultegra. So when installing Garmin Rally RS200 pedals in place of Ultegra PD-R8000, your saddle should be raised by 2mm.