Advice to new TP-Link Archer A7 owners

Picked one of these up via amazon and I'm failing to get OpenWRT on it. Feeding the bin in the GUI = invalid file type no matter what it is named.
Archer A7 v5.0 (says 5.8 on sticker)
1.1.0 Build 20201120 rel.50399(5553)

Also failing at doing TFTP as per docs. Only tip I didn't see in the docs is setting Tftpd64 to bind to the 192.168.0.66, if you don't the server will change to a NIC that is active while router is off. I approved the firewall prompts, and also just turned it off but I never see a request come into Tftpd64. Held the reset switch for ten seconds, also held it all the way through boot, power light stops blinking at 1:45 and held it to 2 minutes.

My first time trying TFTP, maybe something basic wrong?
tftpDIR