In the Appearance tab, I have no option for no. of active plots, only for Plots Shown--but that's for the legend. I'm using 2009; perhaps you're on a prev. version?
The NaN trick works yes; I could initialize all charts with NaN at the start. Still that seems somewhat cumbersome. Either that or set Active plot = 0 with 20 property nodes; about as messy. Stacked sequence? 😮
