Update: This feature has been added in version 2017 R6.1.
To disable sending User-Agent header:
request.UserAgent = null;
To manipulate Accept-Encoding header:
request.AutomaticDecompression = DecompressionMethods.None;
request.Headers[HttpRequestHeader.AcceptEncoding] = "custom-value";
request variable can be created like this:
var creator = new HttpRequestCreator();
HttpRequest request = creator.Create("url");
HttpRequest request = (HttpRequest)WebRequest.Create("url");
Unfortunately, it is not possible to achieve this in current version.
However, it is very easy to implement it. It will be changed in the near future.
If you are interested in a beta version, please let us know.