I don't know about the struts, but I personally avoided that issue with my rack.

I use a hitch rack that easily tilts out of the way on my SUV.

I don't add weight to doors of any kind since several doors in my house started pulling away from the hinges because of the ex-wife hanging clothes on over the door hooks. I also had the hinges on an old car door start to pull out when I was using it to give myself very little extra leverage to get out of the small car for a couple of years.

Hinges are designed with a certain amount of tolerance for overloading, but I would expect your Durango's lift gate to wear out sooner if it continually has the extra weight on it.

Not a real answer to your question, but some advice to look for another option that would probably not cost any more.