I've tested it, and it works. I tested both day and night cycles, and the indoor areas. Although I found the extended areas to be lacking - the entrance to the small western building in the lighthouse's compound is on the east side of the building's exterior, but the interior map has it on the west side. Also, the basement map from IWD has a non-intractable ladder. These maps don't really fit the area. Also, the use of Orrick's Tower entrance for the base level of the Lighthouse, and then a library tower level for the 2nd / top level of the lighthouse are not suitable. All in all, I found the maps to be a distraction from the content because they didn't fit.
As is often the case with modding, I think "less is more" applies to this component.