Do you have 64 clients on the network or on a single machine?
If I understand you correctly, the problem is that you need to address messages to different clients. Think about it, maybe you did not think of something at the architecture stage? After all, if you use broadcast packets, then to address a particular client, you just need to add the necessary prefix to the OSC address. And filter the data on the client side. You might even like the idea of doing a simple route on the client: if it receives a prefix with an IP address, it checks if that address matches the machine address, and if it doesn’t, it accepts the address ‘as is’. This way backwards compatibility is preserved.
I don’t know, maybe it was OSC you needed, but there is NetMQ for such scenarios. But I’ll note separately that I didn’t really understand your basic architecture and about the boot lag.
Maybe this will give you some ideas:
osc_example_multi.vl (46.1 KB)
osc_example_multi_custom.vl (70.2 KB)