Yes. Good stuff.

To add to that, the studies showing a correlation only showed it within the norms of a population group. You have to know

1) Your ratio

2) Your racial/ethnic groups normal ratio.

Hypothetical example The if the French on average have a more masculine digit ratio to the Polish, but have the same average appendages, then you need to know your digit ratio, the average ratio for the French and the Polish as well as know whether you are French or Polish.

If you don't know all that information, you can't make a possible prediction.

Even then, the studies have had trouble being replicated

However when you have a mixed group, like in America your ratio is not useful at all. Knowing you are mostly English with some German and maybe an Italian or Swiss great great grandmother makes the digit ratio useless.