graftcp: I just found and now love this little security tool for forwarding all TCP traffic from a process tree over socks5 proxy.
I start a socks5 proxy using ssh. Then, I start zsh using graphtcp. Then, I run librewolf from zsh, and all librewolf traffic goes through the socks5 proxy.
I don't totally understand how it works, but it doesn't use LD_PRELOAD, so it doesn't require dynamic linking of networking libraries. It apparently works with any network access code independent of how its linked, so it works with Go programs, for example.
