Hi Massimo,
I do not understand what it's the real utility of the parameter "amount" in the fan function.
It doesn't seem to produce an usable and aesthetic pattern and also the result it's not predictable: here I've applied to a group of 8 fixtures, using an amount 100% and 50%, the dmx output shows that the intensity of the first 4 heads have changed.
I don't have an idea how I could use this function, for sure it would be more convenient to have an option to "split" the fan, eg. 50% to split the group in 2 parts and apply the fan to these parts in sequence. 33% to split the group in 3 parts etc etc.
Another option could be to apply the fan by steps: each 2 or 3 (or 4 etc etc ) fixtures will share the same values.
For simplicity I'd propose the first alternative, it's very useful for positions and colors because you can easily repeat a pattern - hopefully together with a centre-in/centre-out layout