I think I've pretty much covered the old thread (for the DOS version at least), except for Wicked 7.
Ok, the secret to Wicked 7:
The game keeps a map of interactive objects' trigger areas to check if a lemming walks into one. The blocker's effects is actually done via trigger areas, a sort of "blocker's field" if you will. Notably, the field is not tied directly to the blocker itself.
Normally, when you create a blocker, the game saves the original trigger areas at where the blocker is, then writes the "blocker's field" trigger areas into the map. Then normally, when the blocker stops blocking (either the ground it stands on is removed, or it explodes), the game restores the original trigger areas into the map to remove the blocker's field.
Notice that the game assumes the blocker hasn't moved from the time it saves the original trigger areas and the time it restores them. This assumption however is wrong: when you explode a blocker, after the countdown goes to zero, it first transitions to a lemming that yells "Oh no" and shudders, before it finally explodes. And the shuddering lemming will fall if you remove the ground it stands on. Yet the blocker's field is only removed when the explosion happens.
As a result, when the blocker is moved this way, the game will "restore" the original trigger areas into the wrong place in the map (where the lemming ends up exploding, as opposed to where it was originally blocking). So you get two effects:
1) the blocker field remains
2) the original trigger areas get transferred into the new position
My lose-4 solution to Wicked 7 make use of #1.