How do I get chickens to breed true. Everything I'm seeing says "Work with the breed for 5 years" is 5 years the magic number? I'm very confused if anyone would clarify this it would the greatly appreciated.
There's no magic number. And developing a new breed will typically take longer than working with an established breed.
From looking at your chart: you should plan to hatch a LOT of chicks every year after the first, because you will be getting chicks with a wide mix of traits, and you will want to choose the right ones for the next generation.
For example, smix3 will pass rose comb to half of its offspring but not to the other half--you'll have to decide which half you want. And smix2 will pass pea comb to half of its offspring. So smix4 (from crossing them) will have chicks with single combs, chicks with pea combs, chicks with rose combs, and chicks with walnut combs (rose + pea). Each comb type will be on about 1/4 of the chicks.
bmix2 is small, and smix4 is large. So your "final mix" is probably medium sized. But if you cross them back to bmix2 and pick the smallest birds, or cross them to each other and pick the smallest birds, you will get some that are smaller. Repeating for several generations will probably result in birds that are smaller yet.
You will have some chickens maturing much faster (Leghorn influence) or much slower (Brahma influence). You will have some that are better layers than others, so you will probably want to raise quite a few hens to maturity to evaluate the egg laying qualities.
And then there's selection for temperament, and maybe for body shape.
Even ignoring feather color and leg color, there are lots of traits to consider.
Time and number of chickens both make a difference. If you hatch thousands of chicks per year and pick the ones that are just right in every trait you can check, you will get offspring that breed true for those traits in a relatively short amount of time. Your chart has 4 levels of crosses, so figure at least 5-6 generations to have any traits breeding true. I don't know how many generations you can raise per year--many people only do 1 generation per year, some people manage 2 generations per year.
But if you can only hatch 20 chicks per year, you could easily be at this for many decades.