If you want to try one of the latest version of Chromium on your VisionFive 2 running Gentoo I have created a Pull Request on the riscv Gentoo Overlay. It is for www-client/chromium: 123.0.6312.58 and takes 3-4 days to emerge.
I have it running and it seems faster than Firefox on my VisionFive 2.
If it works for you please comment on the PR and let them know that you have successfully emerged and it.