I think, if I'm picturing it correctly, that you will have PDC working (correctly added) with that configuration, which is what you want. But if your compressor was placed on an aux track, and that aux track had a latency inducing plugin as well, then you wouldn't want to feed the compressor's sidechain with the Klopfgeist track itself, but only from another aux track that Klopfgeist was being sent to. And that's what you've set up, by the sounds of things.
The problem occurs when a lack of PDC is added to the sidechain signal, causing the compressor to be triggered too early. But it only seems to happen in the specific scenario described above, so you don't have to worry when sidechaining between two regular tracks, for instance.