Hello!
This question gets asked 
A LOT, but I'd like a gut check as I'm reading so many conflicting things about crossover settings. In essence, should I set each of my channel pairs manually, or set the receiver to 80 Hz and be done with it? I do care about good sound, and don't mind setting things manually if I can make it better. Here's my system:
SMALL SQUARE ROOM 15' x 20' DOLBY ATMOS 7.1.4
Marantz AV8802a Receiver
Two 
Marantz MM8077 Amplifiers
Definitive Technology SubAmp 600
IN-WALL SPEAKER SETUP
L/R 
DI 6.5 LCR (Recommended 
40 Hz XO)
Center 
CS9080  (Recommended 
Full Range)
Surround 
UIW RSS III (Recommended 
120 Hz XO)
Rear Surround 
UIW RCS III (Recommended 
60 Hz XO)
Height 
DI 6.5S Recommended 
60 Hz XO)
Subs 2X 
IW Sub 10/10 (Range 
16 Hz to 200 Hz)
I'm asking the question for a couple reasons. First, the recommended XO for all the speakers vary wildly. I read that I shouldn't have XO settings with that large a range if I want a well integrated sound. Second, a frustration, my center channel says to use it full range because it has an 8" driver and a passive 10" radiator. But that receiver won't let me set the L/R to small and the center to large. I'm not sure what to do about that or if I should care. Third, I'm using LFE, and not LFE+Main because that's a whole different topic.
I know a 
LOT of this is subjective, but want some rules of thumb or best practices given this quirky system.
Thank you in advance!