And public safety channels here are all encrypted so there's nothing to listen to, perhaps in the US that's not the case.
The vocal data on public safety channels being reported as encrypted does not necessarily say that there could be no vulnerability there. There's lots of control data that may or may not be encrypted, and encryption does not prevent all kinds of attacks here.
But nobody sells radio sets based on mbelib except the Chinese budget brands (e.g. baofeng) which have circumvented DVSI's patent by setting up a local company that sells the patent because they say they own it (even though they have no right to do it, but DVSI can't sue them in China). But all the public safety ones I've seen are brands like motorola and hytera that buy the real DVSI codecs.
But I'm not saying there are no other vulnerabilities. I'm just saying that there will not be many people using mbelib to listen to public safety frequencies because there is nothing to listen to as it's encrypted.