Confusion with the Load Frame Action

Hello there, while I've been developing my game, I went into a very hard problem:

I wanted to make it so you're able to add in your own items into the game, however the "Load Frame" action inside the Animation bar is pretty confusing.

Apparently you can't add in frames to non existent animations or directions. Meaning I have to manually add lots of animations in the object inside the Picture Editor, but even then for some reason, either the left or the right direction works.

How would I achieve moddable items and adding custom animation frames to an active or something else?

Thanks

I confirm experiencing that issue with load frame,
you theorically would have to prepare an active object with a number (max objects) of frames
can't load pictures in empty frames.
As for directions, they seemed to work for me for more than one direction,
always as long as you had that direction frame populated.

If you can "afford" the active picture limitations, it could probably give you some extra manageability for similar tasks
(has some cool advantages, though, like fully customizable dynamic hot spots!)