Should I set the module to different heights?

Yes. More in the long text

It is recommended to adjust the height of the FG module regularly. The rule of thumb is to place the FG module about 20-30 cm above the plant tips. To do this, we recommend checking the distance about once a week and adjusting it if necessary.

The FG module can also be placed on the top spot without any problems, but this can lead to a reduced light output for the plants.