Comment by guitarlimeo

Note that while Godot's formats support being text based (.tscn and .tres) you get a massive speed boost in saving and loading once you convert to using .scn and .res for everything that is over 1MB in size. If you add a high-res model and make it unique because you need to change the textures or something, that already makes your scene as big as the model.

So be aware that supporting text only will become slow once the scenes are big enough.