Apple’s crackdown on multicast
Apple's reasoning is probably this: By far, the most common use for multicast is mDNS. Apple probably supplies Bonjour APIs which you are expected to use for that use case. If you want to do something outside of that use case, you are probably Up To No Good and Apple will need your name, address, and DUNS number just to make sure you aren't.The thing you have to remember is that Apple has shown the world how to run a top-tier mobile platform that supports billions of users while, more or less, protecting everyone's privacy and data from bad actors. They have decided to err on the side of pissing off devs if it came down to that or compromising on this goal. And it's made them trillions of dollars.