I have a custom allocation scheme in my engine because I want my game to run fast and efficiently on mobile phones and consoles like OUYA. I wrote a custom STL allocater and so far every library I use hooks into my allocation system. However there are some libraries that don't support hooking custom allocaters into that I would like to use. So my question is basically this: should I take the extra effort to make sure that STL integrates perfectly with my allocaters and use as few external libs that can't hook into them as possible? Or should custom allocaters just be used for the game engine itself?