Not sure about that. I have a heavy duty nudge bar on the escape, with large diameter spotlights. It doesn't appear to make any difference. My car does not look lower on the front end. Providing the shock absorbers are in premium condition, any front end accessory should not cause a problem.
That is my perspective. Feel at liberty to correct me if i am off base.
I just put a full guard on mine and haven't noticed a difference. They really don't weight that much and I was able to install it myself. Be careful which one you get, some bumpers are made different and require a short wide bracket, while another requires a long skinny bracket. If the dealer tells you you have to cut the bumper, then say no way and look elsewhere.