If you want point-to-point communication between two network namespaces, you should use veths[1]. I think virtual patch cables is a good mental model for veths.

If you want multiple participants, you use bridges, which are roughly analogous to switches.

[1] https://man7.org/linux/man-pages/man4/veth.4.html

That would create an excessive amount of bridges in my case. Also this is another trivial suggestion that anyone can find with a quick search or asking an LLM. Not helpful.

I'm not sure why people are replying to my comment with solutioning and trivial suggestions. All I did was encourage the thread OP to publish their notes. FWIW I've already been through a lot of options for solving my issue, and I've settled on one for now.