Seems like a bad way to administer fluoride. Fluoride in toothpaste you are not consuming.
Those who drink more water would have a much higher total dosage- the difference between safe amounts and amounts that may cause lower IQ is only double.

Those numbers are to close for my liking. I want to see a 10 fold difference between ‘good for your teeth’ and ‘maybe will F up your brain’.

I would choose a stainless steel option, avoid the aluminum - coffee is acidic.