I am having issues in a game I'm GMing with bags of holding and portable holes. While most people have a natural inclination to put the two inside one another, my players considered ripping holes in the astral plane too boring. They have asked about doing the following things with the objects amoung others. (If I say portable hole, there is a good chance they have also asked doing the same thing or similar with a Bag of Holding)
Filling the portable hole with rocks then swinging the hole attached to a board to drop 10 feet of rumble on top of enemies.
Having a druid carry a portable hole in some way form or fashion as an eagle and having an archer shoot down from the sky out of it.
Covering a shield with the portable hole or even using it as clothing.
Using the portable hole mechanics to speed thing up or make enemies fall for long distances, much like the Portal games.
Having a druid cast create water inside a portable hole that has been capped by something and teleporting people into the high pressure hole.
Closing the portable hole with someone half way in between to cut them in half.
All of these bring up a variety of questions.
If unfolded on a wall, does the hole go down 10ft or forward 10ft?
Must the hole stay where it is created? If it just has to stay attached to the same thing it was unfolded on can you then move it?
If you can move it while open, how do these shifts effect gravity inside? What happens to the gravity if the hole is closed with someone inside and opened back up side ways?
(Certain rulings on the gravity tricks can turn the portable hole into a rumble launcher, especially if you open, close, turn, and open the hole while something is falling inside.)
Does the entrance always appear from the same place inside?
Can a portable hole be broken from the inside like a bag of holding?
If you are holding a board with the hole on it and it begins to fill with rocks does the weight change? If you are holding it sideways does it change anything? What if your holding it sideways and a long heavy object is half in and half out while resting on the holes edge?