I love the half wavelength multiple myth...
This:
What a half wavelength multiple of feedline does is present the exact impedance that is present on one side of the feedline (the antenna in this case) to the other side of the feedline (whatever hapens to be plugged into the other end, radio, VNA, MFJ Analyzer, SWR meter, whatever). This would be useful if you were, say, using 75 ohm coax instead of the 50 ohm coax your radio would expect. This is also useful when tuning the antenna with something more advanced than a simple SWR meter. As far as your radio is concerned, it only cares about the SWR that it sees, and as long as that is below 2:1 (any maybe even higher in some cases) its happy.
The half wavelength multiple feedline myth has been around for a long time. Even with a mono-band antenna using such a length doesn't benefit you any.
The DB