Earlier quoted context omitted.
https://ai.google.dev/gemma/docs/gemma-3n#parameters > Gemma 3n models are listed with parameter counts, such as E2B and E4B, that are lower than the total number of parameters contained in the models. The E prefix indicates these models can operate with a reduced set of Effective parameters. This reduced parameter operation can be achieved using the flexible parameter technology built into Gemma 3n models to help th…
Thank you, that helped a bit, although it's still not clear what exactly those parameters _are_. "Per-Layer Embedding (PLE) parameters that are used during model execution to create data that enhances the performance of each model layer." is too vague, and I can't find any other reference to "per-layer embedding parameters" in literature.
Experimenters in the open source tinkering community have done the opposite (copy/pasting layers in existing models to make them deeper) and it seems to work... fine, with minimal post-training on the new, deeper model required to exceed the performance of the original model. So it's not a crazy idea.