Input socket for Image Texture node

I'm working on an ambitious project that involves using Blender's tools and python to create a custom character builder. The goal with this is to be able to re-use assets and properties by just loading the same parameters where they are reusable. I so far was able to pull off transferring Vertex groups from separate objects to one combined object and same for Shape keys, but the current wall I have is trying to do the same with textures.

Currently, thanks to the attributes reading from the Object Custom properties, I am able to have unique data for every object that loads and thus set up the material accordingly. However, when it comes to the texture map, I had to come up with an unorthodox method to get the map I wanted, which involves creating a custom "switch case" ladder to load and overwrite the textures until I get the texture I want. Since the characters I'm building are made up of several combinations of different body parts, this would be extremely difficult to set up, when ideally, I could just have the image loaded by storing the location string or the image name in the Custom Properties and have it apply for each individual object.

Hopefully I'm not asking too much, but if I could just have an input socket for the image texture node to load images dynamically, that would really add a lot of utility and save me the trouble of making endless switch case ladders.

and I know it sounds a little unorthodox, but you can store blender's image data in a custom attribute using python and it recognizes the image as such. But the node does more to the object which is required to use it in this way. So if I could just feed that image object into the texture Node, Every object will have it's texture data loaded dynamically without needing to create a unique texture for every character.

Oh and while OSL would've been an option, I want to take advantage of my GPU for rendering these characters.