I did. That's the third picture I put up. The last picture is the same area after FSDT disappears and the trial ends.. The BSS scenery is in that patch that the FSDT scenery isn't covering. Simple as that.
I think you are missing a key thing, which should be obvious, considering how flight sim work.
When the Trial ends, the objects disappear, but the scenery is still active in the scenery library, the fact the the Trial ended, doesn't mean some part of the scenery are still active and excluding/being excluded, by the other sceneries around.
So, as others said, during the 6 minutes of Trial, the scenery will look exactly the same as when purchased but, if you want to check the scenery as if there was no scenery installed, you need to uninstall it, both because not ALL objects disappear, and because part of the scenery still effect the surroundings, even when the Trial time has elaspsed.