How do you see the differences? I'm certainly in the non-young column, but I think most of the principles (knee angle, straight back, arm angle to body and at elbow) are similar.
For this subforum, if we want to sticky some "good fit" examples, they should cover a wide range of ages, styles, and bodies. This subforum isn't specifically for racer types, but it's also not explicitly not for them. I think it's about knowledge, guidance, and results. Personally I don't know much about tri, track, or time trial fits, so I would not offer advice on them. And since I still use toeclips, I don't know much about cleat fitting and positioning.