If I understand correctly at this time only USB-TTL console method of installation is available.
I can build 19.07.2 version but it may corrupt your flash filesystem.
Nevermind. I just received a V1 router, so openwrt installation was straightforward.
Sorry, I can't help with testing for developing for the new (?) version.
BTW, V2 is not registered on FccID database. And V1 seems to be the only version distributed in Europe (and US, with different firmware).
Thanks anyway