Consider adding a flag to change model temporarily

[woerndl]

I run almost all of my commands with one of the simple models, but for more complex tasks I sometimes want to use a more advanced model. If I were to use --set-model I would have to add it to every command I run (to set and reset), changing the config.yaml way more than necessary. Do you think it would make sense to add a flag like --model or --use-model for single command usage that differs from the default model in the config?