Hello, I have what I thought was a simple question but can’t find a good answer. I need to move the exiting interior drain on a flat roof as a skylight is being installed there. It is a small roof with a 2 round drain currently. The plan is to replace it with a scuppper . Issue is where scupper would go is righ above a door/window such that water needs to be caught and diverted. all the leader boxes I have seen have a downspout going right off the bottom which wouldn’t work as that would cross the window. So I need a leader box with a horizontal exit or can the scupper just flow into a standard horizontal gutter? Any feedback would be much appreciated