Hi!
No problem mate, you explained yourself really well

The only thing is, that even if i map it in a "free place" it will always need that "free place" to be re-colored because the only space left free is not generally used by the skinners.
Here is an example with a great skin by Zargos: you can see that the only space left free is colored completely in light blue, so if you wanted a canopy in light blue it would be perfect, but it wouldn't be so if you wanted one with the right colors. You would still have to repaint that aerea in order to get the right look for the canopy.

I choosed to map the canopy where it was previously mapped because i thought it would be easier for a skinner (even a non expert one) to track down the mapping and repaint it. I personally did it so (and i'm really "exécrable" as a skinner

), using paint for recoloring that aerea in order to get the right look for the canopy.
I don't know if it was the best decision (this is my first public mod, so i'm not really an expert) but it was a compromise solution between different choices. I hope you can understand me.
But i'm really glad you have some constructive criticism, because it's important for me to hear it, as it's always possible that i'm not able to notice things that for others are plain.