[yuzhongw-nvidia]

Reduce main and MTP token counts over the gradient-normalization group before computing each microbatch ratio. Preserve local logging counts and pass the group explicitly from GPT and Hybrid models.

Document the accumulated-microbatch objective and add one parametrized gradient regression against an unpartitioned cross-entropy reference.

Related to finding 3 of #7452.

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/claude strict-review

[Connor-XY]

@yuzhongw-nvidia @cuichenx, linking the remaining coordination item from #7452 finding 3: this draft targets DP+CP token ratios, while #7498 targets CP normalization and explicitly preserves its existing DP/microbatch objective.

Could you agree on the intended objective and consolidate the overlap, including unequal DP/CP valid-token counts and accumulated microbatches? Please link the agreed scope and regression results back to #7452. Both proposals are still drafts, so the remaining task is reconciling and validating them.