Could companies like Facebook, Google, perhaps CloudFlare detect this is happening in anyway I wonder? Are there any characteristics of the non-FB certificate c

Could companies like Facebook, Google, perhaps CloudFlare detect this is happening in anyway I wonder? Are there any characteristics of the non-FB certificate connections that could reliably be detected either in the headers sent to FB, or via client-side JS? How about comparing the IP address of the request with the IP address reported in requests to the FB server with the IP reported if you make an XHR call to a different domain endpoint that returns your IP? That would compare the physical browser's IP with the MITM 'requestors' IP? If enough of the centralised sites and CDNs look out for this it would render it a lot less effective. This also turns a undetected user security/privacy problem into an in your face "firewall" from the user's point of view. Now the user asks their tech friend "why can't I see FB" and their tech friends sets them up on a VPN. Apologies if this is hand wavey I'm not a network or security expert but I am curious about this.