Should I give it a try? My final goal is to have an LTE USB Dongle connected to the USB port and transfer the network to an RJ45 Ethernet port.
fwiw, the F9K1119 v2 is a Realtek device.
There is no openwrt support for Realtek devices.
Can't find any info on v1.
The F9K1119 (v1) has the same FCCID as the supported AC1750 F9K1115v2 (https://openwrt.org/toh/belkin/f9k1115v2) and works fine using 19.7 firmware.
I am running 19.7.7 (ar71xx) on mine but I've tried many methods to get 21.02rc2 and snapshots installed (ath79) to no avail. The 21.02rc2 sysupgrade bricked it actually, and I had to figure out how to recover:
i.e. Hold reset to flashing yellow, open 192.168.2.1 and load the OEM firmware. No other firmware worked, and the OEM took two tries for me (loading it had a different LED response vs any other). :-/