Screen Mirror iphone to Tv with free netflix streaming

[#1]

Can I still use my free netflix streaming on my phone when I screen mirror to a TV? The image would still be on my phone and connected to the TV via a cord (the Wecast l8 cord). It isn’t on a wifi network. So as far as I know, you shouldn’t be able to tell if the netflix is playing aswell on a larger screen? Im just hesitant to test this all out because I don’t want to be charged with a huge bill if it’s going to use my regular data to play the netflix instead. 

[#2]

I think Optus' official line would be something like "our data free streaming offer is designed for mobile handset screens and not a big screen experience" but I'm 90% confident it'll still be data free with THIS set up. Things like Chromecast would use a different DNS and as such will not be data free.

Just keep in mind with data free streaming, it's throttled to 1.5Mbps which wouldn't look great on a TV IMO. If you're happy with it though then it's no big deal

[#3]

Just to add to @SamSam whilst away in my caravan I sometimes use a Miricast dongle to cast from my phone, reasonable picture on a 24 inch screen but at home with a 55 inch screen not such a good picture.  

Does solve the problem of data being charged.

Dave