There is a block diagram in the manual on page 137.
Take a look at it, you can see where the tapping points are in the signal path. The “Post Preamp” taps the signal before the Deep Preamp.
The tapping points of the tie lines are not drawn in, but the tapping point for them is guaranteed to be directly behind the ADC. Perhaps A&H could add this to the text field “Input Patch”.
And yes, I would say that if you look at it, “Post LPF” is the same as “Post Filters”.