Little bit off topic, but I generated a zettelkasten from C2 Wiki. There is a zip file that you can download that has all the wiki entries from 2015[0] in html format. Used pandoc to convert to markdown and then did some sed scripting to fix the links and remove some boilerplate. I can open it on Obsidian and see that OnceAndOnlyOnce wiki entry has 1,470 backlinks. It's little bit slow and I can't open the Graph view, but otherwise it usable. Tried to open the folder with VSCode and then expanded backlinks sidebar. It resulted in "EMFILE: Too many open files". Is Foam using some custom logic for linking files together. I saw in inbox.md some auto-generated text for dealing with markdown links.
What I learned is that one folder with 36000 files is not a good idea.