Hi, I love this. I have been wanting something like this for a while. Personally, I desired a coin instead of a bill. 2-3CM thick coin made with material good

Hi, I love this. I have been wanting something like this for a while. Personally, I desired a coin instead of a bill. 2-3CM thick coin made with material good for radio security and longevity would be neat. A phsyical 'coin'. Any plans for something like that? Any reasoning against it?