If a project is successful, it isn't 99% done; essentially it will never be done so long it is alive, supported, and/or used by anyone (I won't get into semantics here).
As others have pointed out, many of those things should be done way earlier as part of the development, AND as part of the ongoing development/maintenance after launch.
On another note I'm also skeptical that a project should ever be 100% done even if that was possible. I had the privilege of working on a project during the whole lifecycle, including when it was deprecated and eventually decommissioned. It was very pleasant to go through all of the open Jira tickets for this product and close them as Won't Fix forever. All of those features, bugfixes and enhancements were never implemented. The project launched, lived, and died without them, and it was fine.