How can I make assets accessible to players for modding? - unity3d

Question

My game includes image files and json configuration files that I would like to make accessible in the deployed game's folder structure so that players can easily edit or swap them out.
I have considered/tried the following approaches:
My initial approach was to use the Resources folder and code
such as Resources.Load<TextAsset>("Rules.json"). Of course,
this did not work as the resources folder is compiled during builds.
I investigated the Addressables and AssetBundle features, but they do not seem aimed at solving this problem.
After asking around, I went for using .NET's own file methods, going
for code like File.ReadAllText(Application.dataPath + Rules.json). This seems like it will work, but such files are still not deployed automatically and would have to manually be copied over.
It seems that the StreamingAssets folder exists for this, since the manual advertises that its contents are copied verbatim on the target machine. I assume that its contents should be read as in the previous point, with non-Unity IO calls like File.ReadAllText(Application.streamingAssetsPath + Rules.json)?
So yeah, what is the 'canonical' approach for this? And with that approach, is it still possible to get the affected files as assets (e.g. something similar to Resources.Load<Sprite>(path)), or is it necessary to use .NET IO methods to read the files and then manually turn them into Unity objects?

Answer 1

After asking the same question on the Unity forums, I was advised to use the StreamingAssets folder and told that it is necessary to use .NET IO methods with it.
An example for how to load sprites as files using standard IO can be seen here: https://forum.unity.com/threads/generating-sprites-dynamically-from-png-or-jpeg-files-in-c.343735/
static public Sprite LoadSpriteFromFile(
string filename,
float PixelsPerUnit = 100.0f,
SpriteMeshType type = SpriteMeshType.FullRect)
{
// Load a PNG or JPG image from disk to a Texture2D, assign this texture to a new sprite and return its reference
Texture2D SpriteTexture = LoadTexture(filename);
Sprite NewSprite = Sprite.Create(
SpriteTexture,
new Rect(0,
0,
SpriteTexture.width,
SpriteTexture.height),
new Vector2(0, 0),
PixelsPerUnit,
0,
type);
return NewSprite;
}
static private Texture2D LoadTexture(string FilePath)
{
// Load a PNG or JPG file from disk to a Texture2D
// Returns null if load fails
Texture2D Tex2D;
byte[] FileData;
if (File.Exists(FilePath))
{
FileData = File.ReadAllBytes(FilePath);
Tex2D = new Texture2D(2, 2);
// If the image is blurrier than what you get with a manual Unity import, try tweaking these two lines:
Tex2D.wrapMode = TextureWrapMode.Clamp;
Tex2d.filterMode = FilterMode.Bilinear;
// Load the imagedata into the texture (size is set automatically)
if (Tex2D.LoadImage(FileData))
{
return Tex2D; // If data = readable -> return texture
}
}
return null;
}