I don’t know why the ip address should be necessary. The computer is shutdown or standby. The network card i only powered by the 5V standby power from the PSU. The NIC only do pattern matching to find a packet with the magic packet format and his own mac address.
I checked the NirSoft’s WakeMeOnLAN tool with “IP Address of the device” and indeed, it sends the UDP packets to the ip address of the computer. Is also send an arp reqeust before to get the mac address of the remote computer. As i wrote above, it makes no sense to me because there is no ip stack available in this state. I have two computer with a MSI mainboards and both boot normally with the magic packet send to the broadcast ip.
A packet capture from the remote computer would be nice for further debugging. To check if the broadcast packet is even arriving on the other side.
If your really need such a magic packet you could try to use the traffic-generator tool (/tool/traffic-generator) with inject or inject-pcap.