Where to find ath79 (nand) release images?

I'm interested in migrating my device (netgear WNDR3700v4) to 19.07.4 for ath79 but am unable to find the firmware in the release tree. Both ath79 device status pages show the target as "ar71xx-ath79", but I only see the build under ar71xx/nand. That directory under ath79 has nothing built.

The migration page (https://openwrt.org/docs/guide-user/installation/ar71xx.to.ath79) notes that "images for some devices are not built for releases, because of issues with limited flash size", but this device has 128MB NAND flash so I wouldn't expect that to be the problem.

Is there another reason the image wouldn't be stable enough to include with the releases? Since the status page doesn't list any issues should I expect things to work if I build from source?

Thanks

https://downloads.openwrt.org/snapshots/targets/ath79/nand/ (snapshots or >=20.xy.0 only, NAND support wasn't ready for openwrt-19.07).

I too find it a bit confusing, the wndr3700v4 is on both the ar71xx-ath79 and ath79 lists, but I do not see a release for them. There is a snapshot image mentioned on this page (via "Firmware OpenWrt snapshot Install URL" label):

I tried that image by the tftp method, but it would not load regardless many tries. I re-flashed the ar71xx image (19.07.06 as of this writing) and restored backup configs to get it back to operational.

I have a couple Meraki MR18s running on ar71xx. Tried getting WPA3 working but it seems it's only supported in ath79. Snapshots has images for MR12 and MR16 but sadly nothing for MR18.

If I am to compile it myself, where would I start?