But before it is merged it is better to test flashing from factory to Openwrt.
FYI, the current ath79 wndr3800 snapshot returns this on wndr3800ch:
sysupgrade -v /tmp/openwrt-ath79-generic-netgear_wndr3800-squashfs-sysupgrade.bin
Device wndr3700 not supported by this image
Supported devices: netgear,wndr3800 wndr3800
Image check 'fwtool_check_image' failed.
Is it advisable to use the -F option, as suggested in this previous thread? Porting guide ar71xx to ath79?
Yes you have to use -F to go from ar71xx to ath79. -n is also advisable to make the firstboot scripts rebuild the default config files, as some things related to wifi and possibly other systems will be different. sysupgrade -n
of course erases your configuration.
Would I be able to restore from backed-up ar71xx config, after using -n?
Mostly. Watch out for the wifi "path" being different, and the switch config could be a different format as well. Be prepared to not have wifi access after flashing.
A backed up config is just a tar file of the config files, so you can examine them offline.