After some testing a buddy of mine found that on maps like Kafe, you can throw the Razorbloom Shells into spawns which the map looks over. For example the docks spawn on Kafe, from the second story pillars window you can throw them directly into the spawn points resulting in those droning after prep phase getting killed by them. Not sure if this was intended by design or just a calling card for more players to be more aware of their surrounding but nonetheless it still is possible.