You can give them a credit for putting a honeypot on top of their zk implementation, (next to Zerocoin and Zerocash) that for decades existed on a paper only
(It was executed badly though with a bug)
zk proofs came a long way to be so efficiently small as they are today, even ethereum ecosystem did a great job in exploring zk
Ton of good discussions about zk implementations on https://zeroknowledge.fm/