Hi,
Regarding "We do want to simulate situations where the browser has no cache at the start of a test...", actually Vuser always starts with "empty" cache (until you don't use web_load_cache API).
Also, we "clean" cache between iterations when "simulate new user" flag is enabled.
Regarding HTTP headers, we're trying to use in replay the same headers as it appeared in record.
You can compare "caching" headers in Browser and in Vuser Replay to validate the possible difference.
Then, you can instruct Vuser to send appropriate headers if it required.
Regarding "Also, does the setting you indicate only take effect for parts of the test where we have allowed browser cache? (That is, pages subsequent to the first page loaded.)"
That is correct, you can enable "Check for newer versions of stores pages ..." only when "Simulate Browser cache" is enabled. And as I mentioned we have API (web_dump_cache / web_load_cache) that allows to start replay with "non-empty" cache. In this case "If-Modified-Since" header will be sent just with the first page downloading.
Best regards,
Leonid.
