Hi Damian,
What I observed is that the first mode is actually represented by Individual mode number=0 in Mode Selector Properties and not by 1. In your attached Mode_selecting.osd file, there are 12 modes generated (0-11) and not (1-12). So to select let us say, mode number 12, we have to set Individual mode number to 11 and not to 12 otherwise, I see an error if I connect Spatial Visualizers to the Mode Selectors and the final output after Power Combiner 4×1 is also different.
Please confirm if it is the right observation.
Cheers,
Ahmad