Interesting, but when all is said and done, your problem with the spokes was like due to too low tension and not due to spoke strength. IOW, I doubt that you put over 730# of pressure on any singe spoke, yet they broke.

Many inexpensive machine built wheels (most lbs bikes in the 400 to 1200 range) don't have adequate tension for heavy loads long term. FWIW, people have toured tens of thousands of miles on those specific wheels without problems due to weak spokes.