Not saying it's wrong but i would take a lot of that strength test with a grain of salt. for 1 none of his shear tests were actual sheet tests they were all bending tests. The failure mode tells you more then any sort of "strength" numbers he listed.
1/4" would probably be best. As far as strength goes if you build it right i doubt you'll ever load the thing enough to get close to it's failure load.
If what i drew is similar to what your doing the square at the end that i labeled as, not adding much strength, might look good as a 1/2" x 1/2" banding so the same amount of solid banding is shown in both directions.
Also thanks for that Frank Howarth video link that was a good vid.