Thanks for the post! Currently, all projects would share the same set of result statuses and these are not customizable on a per-project basis.
We do have a feature request for customizable statuses on a project basis and I have added your vote to our existing feature request for this so that our product managers can prioritize this accordingly. Unfortunately, we do not have a specific timeframe/ETA to provide for this yet. The best place to receive updates on this would be our blog, as we always publish a new post that details the new features/changes to TestRail:
In the meantime, you might be able to implement a UI script which hides specific statuses in the ‘Add Result’ dialog menus on a per-project basis. We haven’t tested this ourselves, but you can review our documentation for UI scripts here.
You may also be able to find UI scripts posted by other users in our forums and use those as a starting point.
Hope this helps,