Monsters can zap wands of opening at you, which causes items to randomly fall out of containers you are carrying. (For symmetry, the hero should probably be able to do the same to monsters that are carrying containers.)

When a door is hitten by an opening beam, it actually opens, rather than becoming unlocked. Also, any doors adjacent to it will also be opened (for the “double doors” that appear in some special levels).

Remove the spell of knock entirely in favor of the wand already being a good enough source of opening magic.

Nerf the spell of knock in comparison to the wand of opening: it should be a melee-range spell (or a beam with range 1), and possibly it can’t be used to open containers until you are at least Basic in matter spells.

Zapping an opening beam at a closed, unlocked door opens it. Casting knock at Skilled or Expert lets you unlock and open all at once.

Hitting a statue with a wand of opening (possibly the knock spell too, but it might be nice to let the wand have a fringe benefit) causes it to drop all its contents without breaking.

Zapping the wand of opening (but not the spell of knock) at a trapped door will cause it to blow up.

Zapping a wand of opening down at a bear trap you are stuck in should free you immediately.