rooster and pullet feathering in different breeds

[cmfarm]

I know most breeds the pullets feather out sooner than the roos. But some colors/breeds this is not true of (I bred game chickens at one time and it worked for stripped chicks but not yellow). Does it work for Production Reds? Marans? I am selling some of these kinds that I hatched and straight run doesn't seem to be selling that well. They are 2 weeks old and I can definetly see some diffenences in feather growth. I just wanted to double check so I don't end up with angry customers will a bunch of roosters. I know it isn't 100% acurate (when I did it with the game chickens it was about 90% though, except the yellow ones). Any other breeds/colors it doens't work for (just curious). Thanks!
I put this question in breeds showing and genetics area and didn't get an answer. I did take a look at my Production reds and this doesn't seem to work for them. They almost all have the same amount of feathering except maybe 3 have less (I know there has to be more than 3 roos in with almost 30 chicks).

 

[they'reHISchickens]

We have marans and orps. The marans you can give a good shot at sexing at 3 weeks. The roos combs and wattles really show well.
I wish the orps were as easy. Some say you can sex 4-6 week old orps but I find it easier to sex them when they crow or lay eggs.
The leghorns we seem to be able to use feathersexing. Hens feather first and have tails.
Our EEs we thought the females feather first and have tails, but for every one we get right, we get one wrong , too.
The real problem in any breed is the slow-maturing roo. Some of those can take forever to sex correctly.