But NoviFlow’s OpenFlow switches DO support TLS to the controller!
This is a switch implementation issue and NoviFlow has had TLS between the switch and controller as a basic feature in our NoviSwitch series since 2016. Our NoviWare NOS even supports TLS for Barefoot Tofino based white boxes delivering 6.5 Tbps of OpenFlow 1.3/1.4/1.5 throughput! See www.noviflow.com to download the datasheets.