Do custom headers incur performance overhead on Big-IP?

BIG-IP 11.6.0 Build 4.0.420 Hotfix HF4

We have added an iRule to add http headers from incoming requests so that our application can capture client certificate information:

when CLIENTSSL_HANDSHAKE { 
    set my_cert_0 [SSL::cert 0] 
    set my_verify_result [SSL::verify_result] 
 } 
 when HTTP_REQUEST { 
    HTTP::header insert [X509::cert_fields $my_cert_0 $my_verify_result versionnum serial sigalg issuer validity subject subpubkey hash] 
 }

Functionally, this is working well on test environment. We plan to move this to production but want to make sure all bases are covered. Specifically, we are not able to do performance/load testing in our test environment due to limited connections. Our production environment normally sees 1600 to 2200 simultaneous connections. I can't seem to find any article or documentation on the web regarding any performance hit with such custom headers. That said, the feature is well documented and seems to be a standard way of manipulating inbound/outbound traffic. Are there any other recommendations or metrics that I should look into?

Thank you.