Connected my cross needle SWR meter to the SO239 connector of my FT-710 radio with a patch cable. In fact there are two patch cables, one with PL259 at one end and SO239 at other end and 50 cm long, meant for protecting the SO239 on the radio and another one with PL259 at both ends, which is 1m long, for connecting the SWR meter. The SWR meter on my FT-710 gives only the SWR while the cross needle SWR meter gives forward power and reflected power in addition to the SWR, which is indicated by the point where the two needles cross each other. In FT-710 there is an option to change the meter display to power instead of SWR, which I use occasionally. But I have not seen a way to check the reflected power. After tuning with the automatic antenna tuner in FT-710, the built-in SWR meter will show the tuned low SWR while the external SWR meter will continue to show the elevated SWR in the feedline as can be seen very well in this short video clip taken during a test CW transmission.
You are absolutely right. We are not tuning the antenna, just giving a good SWR to the radio so that the finals will not get heated up. Someone told me that if you operate for long periods, resistors in the tuner circuit can get heated up and go QRT. How likely is that?