Today I worked on porting the Meraki MR16 to ath79, and had some general success:
A lot of things still need to be fixed:
Properly handling sysupgrade from ar71xx
Fixing last LEDs
Currently the WiFi LEDs don't do much.
Not using kmod-owl-loader to load eeprom data to the WiFi chips
Apparently using owl loader isn't good, and there are good alternatives: https://github.com/openwrt/openwrt/pull/1258#issuecomment-411518044
I'm not 100% sure how to go forward; I did speak back in January with the person who originally ported the board to OpenWrt (riptidewave93), but I left the conversation idle until today, where I decided to up and do it (and so far it hasn't been too hard).
For moving forward: I get the impression that https://openwrt.org/submitting-patches should have me squash all of my commits into one and then submit a merge request.