I finally decided to replace the EdgeOS in my Ubiquiti EdgeRouter-X (ER-X) with the OpenWRT. While I was flashing the ER-X with the OpenWRT, I came across few issues which I would like to share here.
Although the guide at https://openwrt.org/toh/ubiquiti/edgerouter_x_er-x_ka works, there are few points you may want to watch out.
1) Initially, I was flashing my ER-X with the openwrt-ramips-mt7621-ubnt-erx-initramfs-factory.tar using Chrome on my Linux machine. However, I got an error while I was doing so. I tried using Firefox on Linux, and I got the same error. Eventually, I tried doing so on a Windows machine and it worked as it should be.
2) Although the guide says you can flash the ER-X with the latest OpenWRT image after you had flashed it with the factory.tar image, it seems you can't flash it with the latest 21.02.2 image with the new DSA setup right after. I got an error complaining the new DSA feature. However, the latest image from the 19.07 branch works. Hence, you may want to flash the device from factory.tar, then 19.07 and finally with the latest image. (this is also mentioned on the guide, but it suggests using an image from 18.06 branch which seems a bit too old).
Apart from the two minor issues mentioned, the process works beautifully. My ER-X is now running with a better supported OS and with more features, e.g. OpenVPN.
