Change the Master Key of Thievery’s invoke power, since it already gives you guaranteed untrapping passively. The new invoke power is to magic map a moderate radius around you (maybe 10) and then teleport you (which will be controlled because the Key gives you teleport control), but you must pick a space within the mapped radius to teleport to.

Reduce the spell level of magic mapping, but also reduce its utility: instead of mapping the entire level at once, you choose a point to center your divination on and a circular or square area, with a radius dependent on your divination skill, gets mapped. After this change, it might be similar enough to clairvoyance to be merged with that spell (the difference with clairvoyance is that it currently always centers on the player; perhaps the new merged spell could instead scale with skill by having a fixed mapping area, but the distance you can target it at increases with skill level.)

This does not change the scroll of magic mapping behavior, which still maps the whole level.

“Partial” magic mapping from a cursed scroll maps a contiguous chunk of about 1/7 of the map, rather than random tiles.

Ranged divination effects (monster detection, object detection, clairvoyance, maybe telepathy) are suppressed if the level is not mappable.

Level flag that prevents mapping as long as the local “boss” is alive (nemesis if anywhere in the Quest, demon lords/Croesus on their own levels). Maybe make the ‘nommap’ field 2 bits instead of 1.