Level Control Loop with AD8314 RF Log Detector

I am designing an RF level controller with the AD8314 Logarithmic RF Detector, using it's non-inverted output (V_UP, pin 6).

According to the datasheet, the loop filtering capacitor Cf should be placed between pin 4 (FLTR) and pin 6 (V_UP).

Maybe I'm wrong, but if pin 4 (FLTR) is an internal current summing node,  why not connect Cf directly between pin 4 (FLTR) and ground like with the  AD8315?

Thank you very much in advance, and best regards.

Alberto