Hello @jackdugan02,
Welcome to the Isaac ROS forum and thanks for the post!
Our official examples use maxShapes up to 252 for the score network. Reducing this may help with memory on Orin Nano, but you might still hit runtime shape errors if FoundationPose requests a larger batch.
Conceptually, conversion is just an offline TensorRT engine build step. As long as you build the engine on the same Jetson (same GPU architecture) and the TensorRT/CUDA versions match what the Isaac ROS container is using, converting outside the Docker container should be fine.
You can convert it outside the container and then pass that .plan file into the container via score_engine_file_path / refine_engine_file_path.