You don't need different products based on curl pattern but you might need different treatment if the areas have different porosity, one is more dry or damaged than the other. If the back of your hair is frizzy that could be not enough moisture, product build up, not using enough styling products or how you wash or dry your hair.

What is your routine at present and do you know what your hair properties are?
2a-2c, medium texture, porous/ colour treated. Three years CG. Past bra strap length heading for waist.

CO-wash: Inecto coconut/ Elvive Volume Collagen
Treatments: Komaza Care Matani, coconut/ sweet almond/ fractionated coconut oils, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss Ultimate Volume, various Elvive
Styler: Umberto Giannini jelly, Au Naturale styling gelee
Flour sack towel, pixie diffuse or air dry.
Experimenting with: benign neglect