Referring to the Linkswitch-PH datasheet, I can see that 220uA is the minimum feedback pin current threshold to put the device into the 'skip cycle' region. The datasheet also states that the feedback pin 'short-circuit' current, Ifb(sc), is between 320uA and 480uA.
I could not find any other information regarding this short-circuit current. Can you please confirm if this current is simply the maximum current the FB pin will sink? Ie, will the linkswitch still continue to operate in the 'skip cycle' region, or can some other behaviour be expected if the feedback current hits Ifb(sc)?