I would get the $1,000 Denon X3300 when on sale on Amazon for $599 (currently $699), or Like-New (open-box) conditions from Amazon Warehouse for $484 (actually this is what I would get).
Yeah, why spend $500 to repair an amp when you could just get the X3300 for $484?
https://www.amazon.com/gp/offer-listing/B01HL8KYAY/ref=dp_olp_all_mbc?ie=UTF8&condition=all
It has no issues powering my 4-ohm RBH SVT Towers to 90dB Volume in my open plan living room 20’x22’x13’ sitting about 18FT away.
My older Denon 3112 AVR didn’t have any issues powering my B&W 802 D2, Phil3, $3K Focal, and $3K Dynaudio towers (LP 12FT away, 90dB Volume).
I also had a 50WPC HK AVR that easily powered 5 speakers (DefTech BP7000, BP7001, CLR3000) that had impedance below 4 ohms.
So I am not very concerned with AVR powering 4-ohm speakers, unless the AVR is the mid-price Yamaha or lower.
The Denon X3000 series can easily power 4-ohm speakers.