Now I ned to stress that I am in no way a "Game maker Studio" expert, however I read somewhere that there was a function called
script_execute(scr, arg0, arg1, arg2, ...);
Could that not be used as an external scripting mechanism?
[object = object or folder]
lets say that the animator has the opportunity to ID certain objects and set an object flag scriptable (just like the flag glow and the like) and is called at every keyframe of the object if set.
If the flag is set and the ID also is set perhaps a custom script could be called (actually preloaded befored called)
let say the script is called id<_of_the_object>.gml and is called with arg0 containing the current time location in the animation, I assuming the script loaded have full access to the "engine" Mine Imator is using when loaded, and therfore could manipulate the animation in realtime, for example create custom move cycle, or custom explode thing or what not....
The reason for a argumented timelocator is so the script could select between multiple timelocators in the script
anyway, just a suggestion, the implementation idea might be completely wrong...