I was wondering the same thing. The Gemma frontier models have the most customization from what I have seen.
Yes, this is even stated in their 3.5 flash documentation. Frankly, I think this is a very strange decision, because the larger the context, the lower the top-p and temperature required. 3.5 flash is simply not suitable for long chats because of this nuance…
It is intentional, they don’t want you to modify those parameters anymore:
Depite that, they are still modifiable trough the API.
The screenshot is from https://ai.google.dev/gemini-api/docs/interactions/whats-new-gemini-3.5

