Pathing obstruction could theoretically be implemented, a script could listen for a new (not an on-fire) sticker, plonking down a bait entity for collision/aggro where the sticker was created at, which may potentially lead to !!FUN!!. The problem lay in the beam, wrangling a scripted timer for multiple turrets (challenging with 0 damage from the beam) and how the engine manages stickers. Searchlights which spawn mines? hmmm...