Is this the correct way to measure the LimeSDR Impedance?

Hello.

I was wondering if connecting a LimeSDR TX or RX port into an external VNA and measure its impedance in a smith chart would actually give me decent accurate results. I.e., is it enough to just tune the center frequency of the channels and measure the impedance or will the impedance itself change when I’m transmitting or receiving? I really have no clue.

My idea was to just know the impedance of an RX port at a given frequency so that I can connect it to an external frequency generator which has an impedance of 50 ohm and then normalize the results I get in RX based on the actual power that RX is receiving. Similarly, by knowing the impedance of a TX port and having a calibrated measuring receiver, I would know the exact power that TX is transmitting at a given frequency.

But would my impedance measurements be correct in the first place? If not, how can I correctly measure the impedance of the TX/RX?

Thanks.