Is it allowed to use the level skip for 100% as long as you still collect all stars ?

You have to enter every level to get all 123 stars anyway. So why do you wanna skip a level then?

because you can get instant doublejump in 1-3 i guess ? and use it for 1-2 and 1-1. Found some nice timesaves and smaller skips so it would save a lot of time