Because time is a trivial concept in a realm where the 4rth deminsion can be manipulated, it's possible that everyones ghost or ghost imprint could exist at all points simultaniously so everything would have an imprint on the ghost zone and ectoplasm would just give the energy for physical matter to interact similarly. So like, everyone is linked to the ghost zone, ectoplasm is just the way of opening that link

I’m only using a geometric fourth dimension, which isn’t related to time any more than our own 3D spacetime is. The most wild time and space distortion probably only happens to particles going a significant portion of the speed of light and whatever the 4D equivalent of a black hole is, not to matter as organized as an ecto-signature or brain. But then again, Clockwork manipulates time in the Danny Phantom universe so…. rubs temples…… ooooouuuugh

Related: I don’t plan to try and explain the reality altering/time control stuff in DP anytime soon because a lot of it is basically magic (even more so than the rest), which is a lot less interesting to me than the basic ghost powers and how they can be exploited.