Just stumbled over another chromium fork:
https://github.com/Alex313031/Thorium
Forum search did not show any entries, so I thought I might share.
The arm64 builds (for raspberry though) works great, it even has googly sync, widevine etc, check describtion for more info.
It works out-of-the-box on legacy rock-5b jammy gnome images with liujianfeng1994 ppa enabled.
For installation/updates one could also use:
wget https://dl.thorium.rocks/debian/dists/stable/thorium.list
sudo mv thorium.list /etc/apt/sources.list.d/
sudo apt update
sudo apt install thorium-browser
I usually like to test https://paveldogreat.github.io/WebGL-Fluid-Simulation/ which also runs smooth with webgl on the rock-5b.
This might be a good choice, till upstream support makes it easier to find a up2date browser with gpu support.