You aren't gonna need it: don't build something now because you guess you'll want it later. Build it when you do want it.
Speculative code used to cost you the typing, and that was the brake. An agent writes it for free, so the brake has gone and the rest of the cost hasn't. Every later session has to read it and work around it.
Say it to your agent
“Remove the plugin system and the config option for other export formats. We export CSV. Nobody has asked for anything else. Keep one function and its test.”