◇ Could this help me?
Yes, and the file-mention habit alone justifies the list. Pointing an agent at a specific file instead of letting it search for the right one is both faster and materially cheaper, because repository exploration burns context before any work starts, and most people never form the habit. Inline shell commands matter for a subtler reason: keeping the output inside the conversation means the follow-up question already has the evidence, which removes a copy-paste step that people silently skip. General practice for anyone working in a terminal, with the one qualification that command names and flags change between releases, so the list is worth checking against the installed version rather than memorized from a post.
Show me which of these actually exist in the version I have installed and the exact current syntax for each: configuring a persistent status line, running a shell command inline from the chat and backgrounding a long-running one, mentioning a file by path with autocomplete, adding a second directory to the session, and starting a side conversation without interrupting the current task. Point me at the official reference rather than describing them from memory. Then help me set up a status line showing the information I would actually use, and tell me which of the five would change my day the most given the kind of work I describe below.