@MikeSilvis I was thinking you could use the timestamps on the SC records for [conditional requests](https://devcenter.heroku.com/articles/increasing-application-performance-with-http-cache-headers#conditional-requests).  It's true that this could require additional information storage (e.g. url, etags, etc) and depends on the server side supporting it.  I'm okay with this RFE being addressed/investigated separately from this PR.