https://securitydocs.cisco.com/docs/umbrella-sig/olh/151392.dita
Browser Plugin X-Forwarded-For Header Configuration (No Proxy Chaining)
browser pluginproxy chainingforwardedheaderconfiguration
https://proxyscraping.org/blog/proxy-chaining-and-when-it-helps
Proxy chaining and when it helps | proxyscraping
A second proxy in the path changes nothing the target can see, because the exit address is all it ever gets. What it buys is that no single company holds both...
proxy chaininghelps