I've been flashing back and forth between OpenWRT builds for debugging and Stock...
Still best combo I've had is when using the kmod-ath10k Kernel Module/Driver (not the -ct version) and forcing the latest beta -ct firmware...
600Mb/s Up from Client @ 80Mhz
450Mb/s Down from AP @ 80Mhz (ignore the displayed 6.0/Mbs and 20Mhz the Station List shows). It IS actually TX'ing at 80Mhz width (if that's what you have set).
Stock TP-Link Firmware I get.. (Limit is other end test machine is wired at Gb link (1000Mb/s))
900+Mb/s Up from Client @ 80Mhz
900Mb/s Down from AP @ 80Mhz
I use the 5Ghz Wifi for Streaming between an Oculus Quest VR headset and Gaming PC. 300-400Mb/s is about bare minimum needed for VR Game streaming wirelessly. OpenWRT did work OK. But, would get slight jitter and pauses sometimes (about the same as older Cisco AP I pulled out using 40Mhz width). Using the Stock TP-Link firmware it's always smooth using 80Mhz width.
The extra 802.11r Roaming control and Full DFS Bands are nice with OpenWRT. I think the -ct Driver/Module just needs to be updated to fully work with the QCA9982 chip properly.