That's true, it's a bad idea to assume an MTU of 1500. Although there is no minimum MTU in IPv4, IPv6 specifies a minimum of 1280 bytes. So if you send your UDP

That's true, it's a bad idea to assume an MTU of 1500. Although there is no minimum MTU in IPv4, IPv6 specifies a minimum of 1280 bytes. So if you send your UDP packets over IPv6, you are guaranteed room for 1232 bytes of payload.