Moderate amounts of heat do not significantly loosen curl patterns. This is what most black people did in the first part of the 20th century. When they stopped pressing they had afros. That is because no one's hair was swing straight back then. If you need to have your hair stick/swing straight that is what causes the perma heat straightened affect.


And that doesn't mean you cannot wear it stretched w/o using heat. As I posted before, I can wear my hair in a very short, shrunken puff:

.
I air dry in twists mostly but on occasion I'll do a blow out with minimum heat or stretch it with old school twisted ponytails.
and see how it goes. There has to be something OTHER than two-strand twists, WNG's and flat-ironing. I'm getting sick and tired of two-strand twists.