This is an old guide, but this person talked about how they made a 1st person dungeon crawler for 2k3 where instead of using the default player, they created an event and then used conditionals to move it and checked the event's coordinates to handle things like switches & doors to simulate it being the player: https://rpgmaker.net/forums/topics/11259/
You could probably employ the same method if you're able to assign 3D models to other types of events that aren't the player/Hero