I bolted an 8-arm reasoning MoE onto a frozen 1.4B Mamba backbone on a single RTX 3060. Here’s the mechanistic autopsy of what broke and what worked.

In three linesA researcher built Mamba-Titan-1.4B-Reasoning (2.54B params MoE) on RTX 3060 by freezing a 1.4B Mamba-1 backbone and adding 8 trainable experts. Trained on DeepSeek CoT traces, the model developed a 'vault door' mechanism: the </think> token isolates at the smallest norm (1.991 vs 4.742 mean) to control latent reasoning termination.

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