Eelco has made several early contributions to NixOS including writing
the samba module among other things, but is more or less inactive these
days.
By my brief inspection, he has not committed to the nixos/ tree since
releasing Nix 2.13 in early 2023 and merging a PR to networking tests
slightly before that. A lot of these tests/modules are actually
unmaintained in practice, so we should update the code to reflect the
practical reality so someone can consider picking them up.
Depending on the network management backend being used, if the interface
configuration in stage 1 is not cleared, there might still be some old
addresses or routes from stage 1 present in stage 2 after network
configuration has finished.