The key to higher fidelity is ditching the AVR and going with a separate prepro and poweramps. You improve nothing by going with another AVR.
And your basis for saying this is?
In the 1990's I used a Lexicon processor as my preamp (first DC1 and later MC1) - at the time, the lexicon was on a par with many pre's and DAC's in performance...
When it came time to update to a HDMI based setup, the later MC12 was far too expensive for my pocket, and I looked at other PrePro's - but found that pretty much universally, prepro's were the same circuit boards as flagship AVR's, with the amps removed. For the priviledge of removing the amps, the price was then increased by at least $1000 (often more)
The AVR's and Prepro's of that era, had a universal problem - they suffered from substantial Jitter issues on their HDMI inputs, Toslink and SPDIF performed on a par with good quality DAC's - I ran audio through Toslink.
From around 2006 to circa 2015, the circuit boards in many AVR's were identical to those in AVP's.
We are entering a new generation now (over the last 2 years) with the 8k HDMI chipsets, new DSP, spread of Dirac etc...
The previous issues with HDMI jitter appear to be ancient history now, and even audiophile DAC's / integrated amps are starting to use HDMI as a primary input.
Whether the previous practice of AVP's and AVR's being the same bar the amps continues is yet to be seen. Current (quality) AVR's have performance that is at the same level as TOTL DAC's of 10 to 15 years ago, not state of the art today - but well beyond "threshold of audibility" difference levels.
I choose to use an AVR as a prepro - driving my external amps, because the AVR's internal amps are inadequate for my speakers... I don't feel I am missing out by this strategy, quite to the contrary, I save a substantial amount of money in the process.