I know project admins can only edit their workflow if this workflow is not shared with other projects.
But I have the following scenario:
One user is project admin in three projects and he'd like to use (and edit) the same workflow for all three projects.
So my suggestion is:
Allow project admins to edit shared workflows if they are admins in all projects which use this workflow.
Thank you very much for this detailled feedback!
Especially the 2nd and 3rd paragraph contain very good arguments.
But regarding the "ALL projects should use the same scheme", I handle it different than you:
In the past (and still in the present in many use cases) we use(d) "Ivanti Service Desk": Everybody I know hates this tool because of the bad UI & inflexibility. That's why we switched to Jira. I administrate about 200 projects. Most of them use our standard, shared company schemes. But some projects have different needs and there are very experienced Jira users who think they are limitated by our default schemes. If we would force them to use our default schemes, it would look like "another inflexible Ivanti" to them.
But this only happens for about 10% of the projects, so that's why we decided to create custom schemes on demand.