Not much point really, because no handheld has a good VSWR, because every radio is too small to act as a groundplane, and the wet bag of water holding it vary in shape, size, mass, electrical conductivity.
in all real world practical tests, the only measurable test is simply that of field strength, as in how string is the signal.
what you can do is get a sheet of metal, drill a small hole in the middle and screw in an antenna to a cable with different adaptors underneath. Then you can with the right gear check where the antenna is resonant, and measure the VSWR. Year back I did some tests using this method and field strength and came to the conclusion that most antennas were dreadful. Crazy claim as for gain, and for those that extended proof they were just an impractical antenna. VSWR readings from that test can’t be duplicated on the radio, because any adaptor, even a small one, wrecks the measurement.
the thing that jumped out was that quarter waves for VHF that work as a ¾ wave at UHf very well. All the clever ones with filtering with coils and capacitors perform ok at. Maybe two frequencies, but are awful at others.