Von Schweikert vr33 question

Placing the woofer on the rear is of no practical concern given the low crossover point.  In fact, it is more of an advantage and reinforces low end response and makes it more predictable.

There are many other designs that give full range response for similar cost--Tekton comes to mind.

You have not given enough info to offer helpful suggestions I'm afraid.

Rear-firing, side-firing (e.g., Coincident and many others), or down-firing (e.g., Vandersteen and many others)... doesn't matter a ton below about 120Hz. You just can't echo-locate down there due to the wavelengths involved... about 10ft at 120hz and a whopping 56ft at 20hz. 

Good luck getting perfect peak alignment at the listening position from the right and left woofers down at those frequencies.  What really matters is how the waves reflect as they bounce around the room, and whether you're getting reinforcement or cancellation at your listening position.  

https://www.jdbsound.com/art/frequency%20wave%20length%20chart%202013.pdf

OP said:
" I understand it allows placement closer to the rear wall."

I assume that you mean what we normally call the front wall in back of the speakers; but a rear firing woofer should actually make placement closer to that wall more difficult.