Sadly, they are doing it in spain, the judges recently stated that they can do it, and few days later almost all of the spanish newspappers had it.

Yes, you can only use it if you where using it in the past, sadly the project seems to be abandoned.

Yes, there are a couple of options, rfbitbanger (currently on the second batch of crowfounding) and adx (arduino digital transceiver).

They also received a lot more complaints for not having enough trans people, just to counter that stupid complaints

More info: https://eldritch.cafe/@cassolotl/111546657870730179

I think is better to not use an standard port and using fail2ban at the same time to avoid automated attacks. If you manage to implent what you are looking for, you are potentially telling an stacker which accounts exist and which not, allowing him to do an easier brute force attack. A typical attacker using a botnet will not be stopped by a single IP being baned, and as son as an IP is banned he will know that this account doesn’t exists. Another option is enabling port knocking.