We have a system that automatically creates tasks via email. We want these tasks to be tagged with appropriate projects, so we're currently putting #project_hashtags in the task description.
This works fine, until someone tries to remove a project from the task. If you edit the task, remove the project from the list of projects, and hit save, the project will remain associated with the task because of the hashtag in the description.
This flow would be improved if Maniphest only read project hashtags from the description at the time the task was created. I don't see much use for reading them later on -- if I'm editing an existing task and want to add a project, I'm going to use the "projects" field rather than typing a hashtag into the description.