Thanks Bruce!
I'm still astounded that no serious audio issues arose from the build - I was convinced from the outset that some tweaking would be required. I'm almost disappointed in a way that the BFD is kind of moot

, I guess I was secretly looking forward to applying all of the knowledge I was absorbing from the forums here

It's sure good to have a third-party remind you that sometimes you do more harm fixing things that "ain't broke".
If anything, the BFD can still serve as a low-pass for the bass shakers, but boy its sure tempting to start dialing something in for the sub just 'cause "it's there".
I'll post some measurements with the mains when I get back next week, and perhaps lean on you all for some guidance (I've never played with phase before).
SLLT? Thought I was just starting to grasp the concept of IB.....hah! you made me Google

Just read some quick blurbs on it, and it may be worth looking at in the new year as well (I just don't yet know how to 'fit' one of these into the current design).
...must.... resist......EQ.........