Trying to fix specific issues with my listening area

90% of time I feel my RX-A3060 is a fine performer on daily tasks. Unfortunately, the other 10% of the time when I want some more extreme forms of music at much louder volumes, I feel like it's missing the magic was contained in my first Yamaha from the 90s (I don't remember the model). It's really hard to quantify without using flowery and poetic language. My current setup is as follows.

Yamaha RX-A3060
2 Klipsch RF-7 II
1 Klipsch RC-64 II
2 Klipsch RP-250S
2 SVS PC-2000 

Like many homes, our floor plan is not ideal for critical listening so we are making due with what we have. There is no perfect seat in our living room.It's designed to entertain 4 people with games,movies and music with a fair amount of compromises. This is a very common floor plan in South Florida.
https://docs.google.com/presentation/d/1KFEgtukOSNj59e6Dz9Q_73dMvEyO-L66w7hzK138V4E/edit?usp=sharing

When sitting on "Couch 1" (see Google doc), it sounds good until you increase the volume on the receiver to "-16.5 dB" and then it starts sounding harsh.I measured the volume at that seating position at 76 dB. I would like to get to 85 dB every once in a while when I'm in the mood for something loud.I think the harshness is coming from the Yamaha/Speaker combo but I'm not 100% sure of it.The room has a massive rug on the tiled floor plus there is a couch facing the "wrong way" in front of one of the speakers. I'm leaning towards the Yamaha/Speaker/Room combo having a timbre that kicks in once you hit -18 to -16 dB on the display.It's like I turned on an instant "Make it sound harsh" button when hitting that volume.

Here's some of the things I'm doing to correct the issue.

I'm ordering some room treatments for the areas I can fit treatments from GIK.
https://www.gikacoustics.com/product-category/acoustic-art-panels/

I turned off YPAO by using the Yamaha Pure Direct feature.
I got some interesting results.
The bottom end was a little less refined but the harshness was reduced a fair amount.
I'm going to try to manually fix the TPAO results using the built in EQ.

Here's what I'm planning to do in the future
I'm going to buy an external amp at some point just so I can off the av receiver hamster wheel
and get an amp that I can count on for years.
I'm going to look at various Tekton speakers if I'm still having issues after resolving everything else.
I haven't added any gear yet because I don't want to buy more gear and still have the same issues.
Hopefully this helps someone else.