Wouldn't every additional person running the same arbitrage code significantly increase the risk of unexecuted trades (on one side) for the others?
That would be true if running the program exactly as it is, with no modifications.
I haven't heard if anyone's started using it yet, but if someone has, one simple way to reduce the risk of orders not filling would be to run the once-per-minute cron job for example at the 30-second mark instead, and try to avoid running the script exactly the same time as someone else. (Not sure if there's an easy way to do that other than by adjusting your computer/server clock though.)
And of course since it's open source, it could be made to run in real-time instead of just once every minute, and that would give you advantage until someone else figured out how to do the same.
I assume you're not running this yourself?
I considered that before I made the program available to everyone, but realized that it would also stop the feedback loop on how it's working, and that would make it much more difficult to continue the development or find out about potential bugs etc.
If I do get a confirmation that someone is using it and is willing to provide feedback on how it's working, I'd be happy to turn mine off and only run mine at times when I really need to for development purposes. (Eventually of course if many people were already running it, then it wouldn't make much difference anymore if I ran it too, and I might as well just keep running it too in order to get more data for further development.)
If you have any ideas or suggestions on how to handle this better, I'd be happy to hear your thoughts.