I recently had some success installing OpenWRT 19.07.2 on my TP-Link WA801ND v5 wireless access point, which I was happy to do since the stock firmware was untouched since 2017.
I’ve documented the process in a video. This isn’t a tutorial with absolutely everything covered — I don’t want to encourage people to brick their devices, so you’ll need competence and proficiency with configuring your network settings in your operating system, and running a TFTP server.
It’s all, obviously, at your own risk. Stay safe and don’t brick your only access point!
Sorry for the inconsistency in audio quality.