Merge Actor Tool missing option to deselect Export Specific LOD

In the new non-experimental version of the Merge Actors tool there is no option to disable "Export Specific LOD". In 4.11 when this was disabled it would merge the actors with their respective LODs still intact. In 4.12+ without this option there is no way to export the intact LODs with their merged actor.

Worked in 4.11.2 but is no longer an option in 4.12 and later.

1. Open the Merge Actor Tool (Window > Developer Tools > Merge Actors)
2. Add an actor to the scene that has a LOD already set up
3. Duplicate this actor in the scene
4. Select both Actors
5. Merge them both
6. Open the Merged Actor in the Static Mesh Editor

Regression: YES

Results: Only the selected LODs will be merged into a new actor

Expected: There should be an option to disable so that the merged Actors retain their LOD levels.

LOD Chain with Merge Actor Tool (4.12)