Well, I've been stretching since January of this year, and it has been a whirlwind of a time! It wasnt easy, but as the months went by, it became easier and easier. Now I think nothing of my mixed texture, I actually see some relaxed parts losing their "straightness" and becoming "curlier" and having more texture.
I have actually come to appreciate this and it's why I decided to transition to natural. it's been almost 4 months and I have found ways to combat the "mixed texture" syndrome. I found a phony pony that has crinkles and curls in it. I use wave noveau and hawaiin silky for moisturizers and leave-in sprays (which I think is helping reverse the relaxed strands) and I keep it as shiny and moisturize as possible.
I just recently had a sew-in though that my sister did for me, i had to take it out though because I missed being able to feel my hair. Plus, the braids were becoming undone (my sister said my hair was too soft and moisturized so the braids would'nt stay - who knew that could be a "problem").
But it's not hard after you understand your hair and find new ways to combat the double-texture dillema.
Hope that helps and Happy hair growing!