Modifying Skeletons (Stages)
This article explains how to modify skeletons.
While this won't have a lot of uses because XFBIN animation editing is not possible yet, it will make it possible to change the spawn points for stages.
First, select the armature you'd like to modify the bones of. In the case of stages, the armature that controls that player starting points has the word hit in its name.
Next, switch to Pose mode and select the bones that you want to transform. In the case of player starting points, the bones should be named dmystart_1p and dmystart_2p.
Now you can move the bones individually (or together) in any way you'd like.
After you're done with modifying the bones' transformation, press Ctrl+A and select Apply Pose as Rest Pose:
If done correctly, the bone's transformation will be applied in the game after exporting the XFBIN with the Export bones option enabled.
In order for stages to export correctly, the Inject to existing Clump option has to be enabled in the export window. Not doing so will cause the collision boxes for the stages to break.