WPA3 support is doubtful. It's a first generation ath9k radio chip, which lacks the hardware for MFP (crypto protected management frames), which is a required part of WPA3.
OpenWrt out of the box assumes each router stand alone, it doesn't offer central management. You could look at add-on control systems like OpenWISP.
Of course if you have a bunch of them laying around unused its a good way to get experience.