Foreground Layer Interaction with Lighting - Multiple Rooftops

I am setting up a map with multiple buildings in a town square. Each building has its walls drawn on the lighting layer, etc... I have foreground layer roofs for each of these buildings, with each set to Conditional Fade, 0% Opacity, Above Darkness.  The problem I am running into is that when a token enters one of the buildings, the other foreground layer objects remain visible, just floating in the darkness (picture included for reference).   My understanding is that this is because they are all "Above Darkness", but if I make any of the "As Darkness", or "Below Darkness", the rooftops are not fully visible. The only working solution I have found is to group these rooftops on the foreground layer, so when one rooftop disappears, they all do, but its not a perfect solution, i.e. a token looking out of a window from one building to another would not show the other building's rooftop, etc... I'm wondering if there is a better solution/setting I am missing that would fix this issue, or if this is the current extent of what is possible.

I start with two versions of the same map. The first version is roofless and shows interiors. The second version has roofs and does not show interiors. The roofless version is a JPG. The roofed version is a PNG with a transparent alpha channel. I then use GIMP to erase everything from the roofed version that is not a roof. The roofless JPG goes on the map layer, and the mostly-transparent PNG goes on the foreground layer. I set the foreground layer to "As Darkness." After adding dynamic lighting, the result looks pretty good to me. Here's a screen shot taken from my player alt account. But now that I think about it, I guess that's just a different way of producing the same result as you did originally.