Thanks for you kind words about GitLab CI. What are the things that a visual editor is really great at? Getting a good overview of the relations between tasks? Seeing what secrets are available?
I believe one thing that cause it is changing a repo from private to public without unchecking Pipelines permission (enabled by default). The new GitLab profile pages looks absolutely gorgeous, but I suspect many will be turned off by the highly visible 'build: failed' icons next to the repos, even if those repos contain nothing but a JSON file.. I personally had to resort to deleting the repo and creating a new one to get rid of it. And on that note, clicking on the '/users/username/projects?limit=10&page=2' next button results in the Overview tab turning blank.
The profile page, however, doesn't seem to update. My guess is that it's a caching problem. I've logged https://gitlab.com/gitlab-org/gitlab-ce/issues/52780 for this.
Having something digital to substitute the whiteboard would be fantastic. Not just for designing the pipeline, but also for seeing the results of an actual run of the pipeline.