On the free and "AI Plus" plan you are only allowed 3.6, 3.1 Pro and flash "lite" (3.5), 3.8 is for the Pro users (the ones paying the full membership)...

Daily usage: normal task, modify this document, do this do that basic office task... anything that requires precise context is doomed for any google-based llm, that is a well known issue of even the gemma models. Only time it has been useful is while using antigravity that makes sure everything has context on every turn therefore wastes more tokens than Fable on the same prompt. Any other LLM will do it faster, burning less tokens and with better results.