AVR decision for 5.1.4

Hey everyone, I've been looking at upgrading to an AVR for a 5.1.4 home theater. Budget is ideally less than $2k CAD, but could stretch it a bit if it's actually beneficial. I've been eyeing either the Onkyo TX-NR7100 ($1800 CAD) or Onkyo RZ-50 ($2200). The biggest difference seems to be the higher power output to the speakers and the addition of pre-amp outputs.

In general it's quite a jump in price from 5/7.1 to 9.1 and higher, and these two Onkyo options seem to be the most reasonably priced for their features. For comparisons, the 9.4 Denon 3800h goes for $2250, and 9.2 4700h is on sale currently for $2520. I've also read there have been some issues with the HDMI 2.1 ports on the Denon products but this may have been fixed with more recent versions?

My LCR speakers are 2x in-wall Polk 265-RT and 1x Polk 255C-RT, surrounds are 2x OWM3, rear Atmos are also 2x OWM3, and front Atmos are 2x Micca R-8C. A bit of a hodgepodge of speakers but due to room size and couch placement, ceiling joists spacing, and general appearance requirements, this is what we settled on.

Would anyone be able to weigh in on whether or not the pre-amp outputs are worthwhile or give their experience with these amps or any alternatives? Thank you kindly for your help!