Why it is useless? You can send or parse any message with library. You just need to write message build or parser program to your own file. N2kMessages contains most used messages, but nothing prevents you write you own messages.
130830 is proprietary message and its contents depends of manufacturer and I do not have any other information of it execpt that first two bytes contains manufacturer code and and industry code (4=maritime).
But for library you can have message builder function like others in N2kMessages:
void SetN2kPGN130830FusionLink(tN2kMsg &N2kMsg,

) {
N2kMsg.SetPGN(130830L);
N2kMsg.Priority=3;
N2kMsg.Add2ByteUInt(0x99A3); // Fusion link
N2kMsg.Add???
}
But there is no way to write more, if you do not know the content os Fusion Link message.
Note that 0x99A3 can be also constructed 4 << 13 || 3 << 11 || 419