This 2 bay model loads and configures the realtek r8168.ko NIC natively.
In my case "ven_10EC dev_8168"
I keep looking because I have some hiccups, the first time it seemed to work fine but when I remove the drive and start again I get several failures.
The static IP configuration is not saved on reboot, each boot generates a different ip and adapter, eth0, eth1, eth2... two by two because the motherboard is dual lan.
MODEL_TYPE="QX690_QX710_20_10"
PATCHED_FIRMWARE="TS-X51A_20230322-5.0.1.2346"
DOWNLOAD_URL="https://eu1.qnap.com/Storage/TS-X51A/"
It loads relatively quickly compared to other models, I install firmware via the web and configure, but I'm still looking.