Toggle the explicit proxy behavior in 11.5.x

I don't believe there's a way to dynamically assign an HTTP profile, like you can an SSL profile (though I can see where that would be useful). I think you could, technically, do a layered VIP approach with an LTM VIP on the outside (no HTTP profile and SSL offload as required), and separate LTM HTTP VIPs on the inside. Switching between them would depend on what you're looking for, and persistence might involve a cookie that you set manually in the TCP stream.

Or open a case and request this functionality.