I got an idea from Evelyn Lane on here that a dumbbell could be used as an anchor point on the other side of a door for full suspension hanging. You attach your rope to the dumbbell using snugglehitch then put the rope over the other side and tie a noose at the top. Would this be a bad idea? Would the door come off its hinges with the weight of your body?
This method is not about the weight of the dumbbell. It basically works the same way as door anchors for resistance bands. You wedge a piece of rope or strap between the door and the doorframe, and tie an object to it so that it can't slip through the gap. If you do this and close the door, it's relatively safe. The critical points to pay attention to are: 1) the door must be strong enough (unlikely to be an issue); 2) the door must be able to close securely and must not be able to open accidentally; 3) the gap must be narrow enough so that the object can't slip through.
I believe most doors are strong enough for this. If the door is closed, essentially the whole frame supports the weight, and not just the hinges. Nevertheless, try to position the anchor closer to the hinge side on the top edge, as the door is slightly stronger there.
Using only a rope might not work because it might not fit through the gap. But a piece of strap most likely will. One option is to use a ready-made door anchor for resistance bands (or fitness bands), but it's easy to make such an anchor at home too. The object tied to the rope (or strap) doesn't have to be a dumbbell. It can be anything as long as it can't fit through the gap between the door and the doorframe. E.g., a thick towel folded up into a cylinder shape works fine too. Whatever you use, just make sure the rope can't slip off it.