Alt-tabbing can also shift other NPC locations, such as the BF traders or characters in the main game. In the dungeons this shouldn't cause any serious problems, though.
An alternate (though more complicated) method to get past any dead ends in the BF dungeons is;
Teleporting anywhere (via hex editor)If you stand north west of an outside corner wall, there may be a gap where the 2 walls meet that you can toss a teleporter stone through. For example, there is a skeleton archer north west of the wall around the cursed abbey, that can shoot at you while you are inside the wall. Depending on the layout of the dungeon, that could be useful to get into inaccessible places.