How to hook into engine loop initialization

My game code depends on a third-party library that needs to be initialized (via 1 procedure call) before any of the game code is invoked, including constructors of Actors and UObjects. However, from FEngineLoop init() code it seems that ProcessNewlyLoadedUObjects() is invoked even before UEngine is initialized (and this was confirmed by running the game from non-editor build).

Is there a way to supply a procedure call that will be guaranteed to be invoked before any of the constructors of my game module without modifying the engine source code?