I must admit I still don't see the point. Whether it's double/triple/quadruple of a million or just 3*n+1 doesn't seem to matter much. Of course it'd be better if a "thousand" was just called a "million" then, since that'd remove the +1, but the million milliard system doesn't seem to have any notable advantages otherwise, especially considering every "iard" step is a .5 one, which isn't much cleaner.

1,000 -> 3x0+1 zeroes

1,000,000 -> 3x1+1 zeroes

1,000,000,000 -> 3x2+1 zeroes

vs

1,000,000 -> 1x6 zeroes

(1,000,000,000 -> 1.5x6 zeroes)

1,000,000,000,000 -> 2x6 zeroes

(1,000,000,000,000,000 -> 2.5x6 zeroes)

1,000,000,000,000,000,000 -> 3x6 zeroes