There is a real reason why I did not buy the BBR tuning mag rims of 5, 6, or 10 spoke design...They have problems with cracking and breaking, usually at speed, right where the spoke attaches to the mag rim because of mush less thickness and width of metal to be of much use other than on a pedal bike which results in its failure.
The three spoke mag on the other hand is much more substantial with a huge amount of "real estate" contact by volume of space and width contact with the mag rim, mine have not even shown so much as a minor crack in 2.5 years with 1500 miles and my average cruising speed is 35MPH, so I know it is good for our little beasties that we build...lol.