Are you talking about item budget or lightmap? I suppose you could place it merged with an invisible blocker.
The impression I got was that this is the way screens were supposed to work in the first place? I may be misinformed.
the 128 128 greenscreens were solid, used 0 budget all around, i got a work around for my map now which raised budget by only 2 percent around so im ok now. just sucked to see my entire map no longer bieng solid I tryed that at first but the update broke inv barries so i had to scrap that and used 256 256 floor pieces which only raised it by 2 percent