The middle child of the series. The 12B is the first Gemma-4 that's neither a MatFormer "effective"

model (E2B/E4B) nor a giant (31B/26B) — but it has its own two surprises: it's packaged as a

**multimodal* model with an encoder that isn't there, and its attention overflows a Neuron hardware

buffer in a way the smaller models never did. This is the short, clean port that only needed three

fixes on top of the E4B recipe — once I found them.*