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, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
CO-wash: Inecto coconut
Treatments: Komaza Matani, coconut oil, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume, Inecto argan
Styler: Umberto Giannini jelly, Boots Essentials gel
Experimenting with: going back to basics