So regarding non-despawning magic bombs, I found a specific point at Forsaken wherein it continuously happens, given that you stand at the correct spot and aim accurately as well.
This led to the creation of a lag inducing wall, wherein it overrides the game music, such that you hear cooking sounds when near it.
The amount of bombs that “could” stay on this wall seems to be a lot, since they don’t despawn.
The wall up close
Above, you can see me, aiming at a certain spot and standing on a hut wherein it “happens.”
This is the sweet spot where the bombs don’t despawn