Welcome to our forums and many thanks for your interest in our network library.
As you have found most memory allocations come from the compression/decompression stages. Disabling compression is straight forward to do globally, just change NetworkComms.DefaultSendReceiveOptions:
NetworkComms.DefaultSendReceiveOptions = new SendReceiveOptions<ProtobufSerializer>();
If you only intend to used pure byte then you can go a step further an also disable the serialisation stages (there is a very small additional overhead to sending byte if the serialisation stage is enabled):
NetworkComms.DefaultSendReceiveOptions = new SendReceiveOptions<NullSerializer>();
For more info please see our tutorial on SendReceiveOptions here.