Here's a blog post[1] from last year regarding an open-source implementation of virtual geometry. The linked code is maybe a couple thousand lines. It's not something you'd write in an afternoon, but it's also not the towering monument of complexity that Epic Games pretends it is.

[1]: https://jms55.github.io/posts/2024-06-09-virtual-geometry-be...

Edit: I don't mean to sound disparaging - it's some genuinely cool algorithms. It's just that Epic is incentivized to hype it up, and so you get a huge paper and multiple talks that are designed to make it seem even more impressive.