Yes. The board-linksys_ea6350v3.bin calibration file works with 19.07 and recent versions of OpenWrt just fine. I am using the file now on snapshot r17482 (more recent than 21.02) and have previously used this same file on 19.07 without issues.
It's been some time since I tested performance. The EA6350v3 has been up for ~3 weeks. Nothing special on the WiFi setup beyond turning the power down from 30 to 28 dBm on both radios so that they aren't "shouting" so much louder than the clients in the house can transmit back to them anyway. The 5GHz for the EA6350v3 is on channel 149 and 80 MHz width. The 2.4 GHz is on channel 11 and 20 MHz width. I just tested 2 locations with iperf3:
A) A thin client with a monitor display blocking the desktop wifi antennas and with a couple walls or a mostly open, but tortuous "U" hallway between the desktop and EA6350v3 some distance away (unscientifically measured as around 17 paces). I know the thin client has an Intel AX200 WiFi card, since I put it there I would call this a fairly challenging medium to long distance location.
B) From an Acer Swift 1 laptop right next to the EA6350v3.
A) 187 Mbps
B) 423 Mbps
A) 68 Mbps
B) 73 Mbps
I would not recommend it generally (a wired connection would be best), but I use location "A" over 5GHz to tune my ER-X gateway SQM settings to tame buffer bloat - mostly because I'm lazy and that's the computer I use most often, so I'm already there. I don't notice much difference between location A and a wired set-up elsewhere in the house the few times I've bothered using the wired set up, so the EA6350v3 WiFi seems to be doing just fine without adding any noticeable latency. I'm using the "stock" ath10k-ct that comes with OpenWrt by default.