I hope those who have used REW with their 976 can provide some guidance so I'm reviving this thread as I'm getting ready to use REW (with my MacBook Pro) to check my family room's performance and then use the 976's PEQ feature. I have ordered a boom mic stand for my UMIK-1 microphone, a USB C to HDMI cable to connect my Mac to the HDMI port on the front of the 976, generally getting acquainted with REW on my separate 2-channel system and about to install some new drapes that will address a speaker reflection point. A couple of general questions that may be more about REW than the 976:

1. Does REW recognize the number of active channels in the 976 (e.g. I'm running a 5.1 system)?
2. I have Outlaw's 4-page guide on how the PEQ and bass management work in the 976. Should the sweeps be done at full range on the speakers and then translate the filters below the crossover point (80Hz in my case) to the subwoofer and LFE or do I run separate sweeps at each speaker only below 80Hz for sub and LFE adjustments?
3. I have read and been careful in my 2-channel rig to avoid trying to increase the gain too much where the room is likely causing a dip in frequencies below about 300Hz as it can put a great deal of strain on an amp. However, my 2-channel system does not have a sub. How much gain is reasonable with a sub for dips below the crossover point between sub and small speakers? I have limited any gain to 5db in my full range stereo system. Is that a reasonable amount of gain for filters/corrections above 80Hz?

Thanks for the guidance!