I’m convinced that language sharing can be encouraged during training by rewarding correct answers to questions that can only be answered based on synthetic data in another language fed in during a previous pretraining phase.
Interleave a few phases like that and you’d force the model to share abstract information across all languages, not just for the synthetic data but all input data.
I wouldn’t be surprised if this improved LLM performance by another “notch” all by itself, especially for non-English users.