Question about weeks 1-4

I will hopefully be moving on to most of the PE2 elements in a few weeks, I'm curious as to how essential weeks 1-4 are in the program. I'm fairly confident that I will have the strength endurance to perform the reps for weeks 5 onward and am tempted to start there but should I?

I can see that weeks 1-4 would be beneficial for getting the form down and making some progress with the mobility elements so that they are performed correctly but apart from those reasons is there any other reason to start at week 1? 
I was wondering if weeks 1-4 were intended as a sort of extended de-load phase of training and that by skipping them I may be missing out on some essential rest time. 

For every exercise that you can't pass the mastery test on, you should choose between starting at week 1, 5, or 9. If you think you're on the verge of mastery but just need a little more work, start at week 9. If you're familiar with the movement and find you're reasonably strong in it but still need to develop more endurance, start at week 5. Otherwise, start at week 1. 

 

And of course, the iM component is a separate beast. You may start at week 9, but still need 12 weeks to develop sufficient mobility to progress. In this case, you'll just repeat the week 9 cycle three times.