Fixes: #24806Fixes: #26689Fixes: #27325Closes: #24807
@tommarshall has done us a huge favor with his PR https://github.com/vercel/next.js/pull/24807 which outlines exactly the issue and a pragmatic solution.
I'm not trying to "steal their work", however, the PR seems to have been stuck for some months. I think there's huge value in this for myself and others as essentially **ISR is broken** for people running Next.js at scale 😱
This PR has cherry-picked @tommarshall's fine fix and added some integrations tests around page revalidation and the edge case when the cache size is exhausted.
✏️ Edits are enabled, so feel free great Vercel staff and other maintainers to improve my bad tests or surrounding code 🙇
## Bug
- [x] Related issues linked using `fixes #number`
- [x] Integration tests added