It's still very difficult to verify or ensure that the sites you know you'll need will actually be cached when you need them. For instance, you may not need page XYZ of the documentation now, but you might later when you're coding on the beach, and there's no way to force Chrome to crawl it besides preemptively visiting the page - and even then it might be evicted for any number of reasons!

Batch Save Pocket [1] is my stopgap solution, but Pocket's not at all optimized for documentation.

[1] https://chrome.google.com/webstore/detail/batch-save-pocket/...