We don’t recommend modifying the OttoDeploy file in any way, because those modifications may be lost with new major versions of OttoDeploy (where we replace the entire file). However, if you’re talking about using it as an external data source (since it’s where your file credentials are stored) then that would not cause any issues. You would have to write a custom deployment script yourself using the OttoFMS developer API, but it’s not too hard to do and we have some guides on how to do this.
Have you considered setting up a recurring deployment for your use case? These effectively leverage the script scheduler on your FileMaker server to run deployments, and you could even leverage that as your “service” to trigger the deployments manually if you don’t actually want it to happen on a schedule. Just schedule the deployment for far in the future and use the FMS Admin API to run the schedule early, on-demand. Similarly, you might be able to use the “Rerun a deployment” OttoFMS API to trigger a deployment manually if you never want to set a schedule.
In either case, no your Production users would not have any downtime. What happens behind the scenes on the source server is the file is paused for an ad-hoc backup, and then that backup is sent to the destination server.