That's all true, but work trees are cheap, and the workflow you describe means that your submodules are tracking a branch rather than pinned to a revision, righ

That's all true, but work trees are cheap, and the workflow you describe means that your submodules are tracking a branch rather than pinned to a revision, right? For our purpose that's definitely worse; the submodule is supposed to be a pointer to a specific tree, with that tree being the same for all developers. If we want to change the tree that is pointed to, we should commit and push a change to the submodule ref.