TCMinecartVariants is a sort of add-on for both ItemsAdder and Traincarts.
The resource adds custom models of minecarts filled with ores, which could be used instead of the normal, empty minecarts.
It also comes with a YAML file for traincarts to spawn these custom models already preconfigured.

Installation
Detailed instructions on how to install the assets can be found in the README of the GitHub Repository.

Preview
Here is a screenshot showing the different minecart models added to TrainCarts.