minimum size to pick cloud nine?

[tjg911]

i never grew this variety before and i have 3 plants. all 3 are covered with flowers and several small fruits are developing. i don't want to be swamped with eggplants so i wonder if i pick them at the 4" size will they be ok or must they be more mature? seems i read somewhere that eggplant is edible at 1/3 their full size. since this variety gets large, 8" if i remember correctly, i'd prefer to use them smaller.

thanks,

tom