I would like to suggest something like the On Wall trigger.
What about a trigger to check when a gadget hit a solid?
Practical application. When the player project hit a solid or a phisic object, splash or explode, otherwise you'll need to check what it's colliding with the player.
Actually, when you draw the scenario with many type of solids, like grounds, walls, ceiling, you'll have a huge work doing each collision detection for each type of wall.