Now you can't drop blueprints.
Add it to zapper.lua to delete them on Z.
local function zap_key(event)
local player = Player.get(event.player_index)
if player.cursor_stack and player.cursor_stack.valid_for_read
and (player.cursor_stack.type=="blueprint"
or player.cursor_stack.type=="blueprint-book") then
player.cursor_stack.clear()
end
end
Event.register("picker-zapper", zap_key)
