If I fixed a portable hole on the front of a large flat shield, looking at the front of the shield, I would see a a 5 foot deep hole. BUT, looking at the shield from behind, would there also be a hole? Would the back be flat and untouched?
Would arrows shot into the hole re-appear 5 feet behind me? Would they just disappear?
I'm sure standing behind the shield, the arrows would not hurt me, as the ground or walls a hole is affixed to are unharmed after the hole is removed, so no permanent damage is done.
From the front, would the hole be limited by the thickness of the shield? Would the hole extend 5 feet back through empty space leaving a hole in my torso?
Would the hole GLUE things into a fixed position behind it? Like an invisible thumbtack made of negative space? Because a hole in a wall opens a space to hide in, crawl through, but how solid are the walls? you cant go sideways inside a hole, but is this because you are in a rock wall, and the unaffected rock is blocking your path? or is the hole itself the unmovable wall? Would there be no resistance, if there was no physical material blocking your path? i.e. COULD an outside object enter hole-space from the side, if there was NOTHING there to block entry?
To make positional questions easier, z-dimension is the depth of the upright hole, front to back, and x is shoulder to shoulder, Y-dimension up and down.
If I stood behind the shield (say, 5mm thick?), would the dimensional hole cause me to be separated from my lungs? If so, would they still function on the other plane? Would blood flow cross the threshold in x/y directions unhindered? Would a solid force stop my heart/lungs from oxygenating the rest of my body? Would it continue to work as expected, but just do so invisibly? Would I be "thumbtacked" into position and held, until someone in the front peeled the hole away? Could I come and go from behind the shield at will, because the dimensional adjustment only applies to the front surface of the shield along the x/y axis' leaving the back unaffected?