Most "FDX export" is a one-way street. arqo's is bidirectional and lossless — scene numbers, revision marks, locked pages, all-caps slugs, character extensions, and even your custom MORE/CONT'D rules survive the trip.
Every arqo script has a Fountain mirror you can grep, diff, branch, and version-control. Lose access to the app? You still have the script in human-readable text. Lock-in is the opposite of production-ready.
Title: Night Tapes Author: Maya Iglesias-Bautista Revision: Buff # Act II INT. STUDIO BOOTH - NIGHT The reels spin. Marisol leans toward the mic, listening. MARISOL + You said you'd play it once. It's been three nights. CALEB - I know what I said. I'm asking you to listen. + I know what I said. I'm asking. (beat) Marisol picks up the cartridge. Turns it once in her hand.