History caching expiry

[bencrouse]

In the docs, under caching it seems like the contract is intended to be "HTMX follows HTTP cache semantics". The source code for the history caching seems to only use the URL as the key?

I assume the intent on most requests is to follow the browser's support for HTTP headers like Vary, Etag, etc. How should we think about this with respect to items pulled from the history cache? What's the intended use case for expiration there other than the cache busting param?

Thanks.