Didn't read it all, but tried anyhow. Had a half wave 11m jumper in the truck and had to know.
First thing I did was calibrate at the port saver. Then, I attached the tee and port extended the measurement plane to the tee. I initially did the calibration from 20MHz to 80MHz, but had to bump the stop up to 120MHz. I did not recalibrate, but that doesn't affect it enough to move that dip. Had I been measuring something more important, I would have. The wear on my ports wasn't justified by the minimal change in accuracy in this case.
I then connected a 50Ω terminator to one side of the tee to confirm my jumper length. At 27MHz, a half wave coax looks like an open leaving the terminator the only thing seen at the tee by the VNA. Where SWR is 1, the coax is a half wave or multiple. Coax is thus 1 wavelength at 54MHz.
Then I removed the terminator and stuck just the center connector into the tee to make the loop antenna as described. I did get a nice match, 20MHz worth of BW under 2:1 SWR. Only thing is that it wasn't at 54MHz. It was up around 80MHz.
This was sitting on my wood pile and maybe getting it up higher would have shifted the center frequency, didn't have time to test. I also did no measurements of the pattern, figured a better setup was necessary for that.
The important part is that the power goes somewhere and its definitely worth further investigation. Wish I had time today.