If you are using IFT prep packages then you don't need to read the full curriculum because you can use the IFT videos or the IFT notes to learn what you need to pass the CFA Level I exam.
The IFT videos and the IFT notes cover all concepts you need to pass the CFA Level II exam. However we recommend that you also read the curriculum if you have time, especially the blue box examples and the end of chapter problems.
So, you don't need to read the full curriculum if you are using IFT material and follow the 10 steps study strategy:
The IFT 10 Step Strategy to Pass the Level I CFA Exam