I have a modified version of tm-remote-build on my main machine and while setting things up again on my laptop re-found that I can't use it from WSL. The two args I added to make it work was host and directory.
The command I use is tm-remote-build load folder "$PLUGIN_FOLDER_NAME" --host 172.18.16.1 --port 30000 -v -d "$HOME/OpenplanetNext/"
I can share my modifications in a few weeks when I'm back in Australia.