This amuses me, probably for the wrong reasons.
A raised edge on the front bar, i.e the bar inside the material sleeve, the bar above the door having material joining it to the front all the way along will stop water coming inside the bivvy, strictly speaking there is no need for a peak on a bivvy.
A peak helps if you set up facing the weather, in theory it reduces rain getting into the front of your bivvy. However a stronger wind can blow rain droplets into your bivvy, whether you have a peak or not.
The peak on many modern domes seems to be a part porch, or a cut down porch, with no storm sides.
Not being funny, but I could not justify the money for Trakker, despite having the option to buy them through work!