Hi, a handy way of solving pivot issues with replace actors may be by creating a widget and using the get component bounds node which returns an origin at the centre of the bounds of the actor. You could then spawn the new blueprints at these coordinates. The calculated origin will likely be slightly off dependent on whether the previous actors actually have their pivots in the centre or if they are rotated in world space. However, having all your replaced actors in almost the right spot might save a lot of time compared to trying to drag each individual one to the right place from the origin.
Maybe something like this:
Hope that helps!