Hello tjackson382000.
10 inches is a stretch for ISO15693, but out of the question for ISO14443. I like the Feig CPR74, which puts out 250 mW. It's a module with onboard antenna and a u.fl for off-board. Feig also has higher power (and higher priced) external antenna HF readers that will make your 10 inch distance a lot more doable. Their 100x100 mm antenna works great.
I have built 24 inch across conveyor systems with Feig's older readers that put out only 100 mW, so your requirement is not a pipe dream. Your should try to physically match the sizes of the reader and tag antennas, so your 3 inch tag would talk best with a reader antenna of 2 to 4 inches or so. With a bigger antenna, your tag might only read at the corners.
I am not aware of NanoVNA computing a Q value for you. If it did, you would still have to question whether their method matched that of the appnote. I would concentrate on computing Q per the appnote's methodology, given the profile of the Channel 0 LOGMAG curve, which is yellow by default.
One fun trick I "invented" is to connect a nonresonant loop to port 0, about the same size as my tag. LOGMAG 0 should be flat across the stimulus range. Now put your tag on there. You will see the tag's resonant frequency and get a relative indication of its Q, which lets you compare tags to see which are stronger.
