Maybe consent is not an appropriate term. Perhaps an acknowledgement and a way to say "I don't want this" would be a more suitable approach. I feel like a flag to turn off LLMs is useful. Firefox added something like this in a recent release. I don't know how much they're downloading or how much they run it, nor would I be a good judge if it's necessary or not, but I don't want that functionality in my browser so turned it off.

Extra power and ram usage without your permission, for example.