TBE go for it
As you are well aware they are designed for drinking water and are perfectly safe
The acidic nature of the wort will eventually corrode them

which is why copper wort chillers come out shiny after use BTW.
You will die of old age long before there are any ill effects from heavy metal poisoning
Copper and Zinc the two major alloying elements in brass are a necessary part of our mineral intake any way
Just to put this to bed hopefully for once and for all and to stop people worrying about brass, consuming more than two pints of 4% abv beer per day will cause much more damage to brain and body
But I don't think any of us are going to stop drinking until our health noticeably suffers
