I'm not sure if I'm envisioning what you're describing properly, but if you mean something like the Moryde StepAbove or the Lippert SolidStep, the door will probably be in the way. The way ours is hinged, we can't pull down our steps until the door is at 110 degree or so. That being said these steps come in various widths and you can probably just get one size narrower if that solves your problem (e.g. the 26" SolidStep instead of the 30"). You'd lose a bit of comfort using them but eliminate your issue.
Depending on the brand you get they have somewhat different mounting methods. We've got the Moryde StepAbove setup and they have a flat "hinge plate" that gets screwed to the floor just inside the door. See below. The steps themselves then attach to the hinge plate via a pin, and this pin is removable in a pinch - it's difficult to get out, but lets you completely remove the steps if you're in a really tight situation.
