Hi TychoVII. Glad to hear that my toolkit saved you work. Sight is blocked by whatever you place in the level that has range trace set to block in its collision properties. If there are no walls in the rooms you will thus be able to look into other rooms, enabling creating floating islands and such. You could always place invisible walls if you want to have the look of your first image.
For your second problem with the pawn not being able to look through corners, that’s because you’ve placed the tiles on the inside of the floor tiles, which cause them to block the visibility tracing. If you place them on the tile outside instead, they will allow for vision across corners. However, this will also allow for vision through corners in the way depicted below. I’ll be adding a pillar component in the next patch to fix this, though anything placed within or behind the corner, like an invisible wall, should do. I’ve also resized the walls and placed them a bit lower in the screenshot below, since the walls will seem to be floating if they are placed in thin air with their current scale and location. I’ll be changing the wall mesh to make it more visually appealing in the future, though they are of course just placeholders.
As for placing modular rooms, one way is to do it procedurally like Zeustiak is suggestion. This takes a bit of work, but I created the system with adding procedural generation later in mind, so it shouldn’t be too hard to do. Just feed your procedural algorithm into an array the size of the map, then for each index in the array place the appropriate instanced static meshes in the level at locations found in the Vector Field Array. A much simpler solution, however, is to simply group the actors in a room together. Select them all in the viewport and press ctrl + G. Then click “place actor at anchor”, and after that you can freely copy and paste rooms across your level that should snap to the grid. This will not give you the possibility of having saved rooms stored in a folder, however, and you would have to have a palette of rooms on one side of the level to construct your dungeon with, which you could copy to other levels. Unreal Engine used to have a feature called “make composite blueprint” that would allow you to save such configurations, but I can’t seem to find it. Maybe it has been patched out? Does anyone here know?
@Zeustiak: Thanks for stopping by 
I pretty much figured out breaking up loops on my own. I used a similar solution to the one I sent you a PM about a couple of weeks ago. I sent the same to and he seemed to think I was doing the right thing, so I just went with my original idea. It seems to work pretty well. It is still almost as quick as a regular loop if you put loops per tick to infinite. Here are blueprintue pastes of for loop per tick and for each loop per tick respectively. Plug whatever activates the loop into Initialize and a tick event into the tick execute node. It has a regular Loop Body output and completed output as well as a Tock output (I should probably call it tick, but couldn’t resist) that fires at the end of each tick after the code for that tick has been fired. These haven’t been added yet, but they will be in the next patch. Epic just told me that my previous patch will be uploaded today, by the way.