If I understand correctly, you are looking for a GUI scron management tool, where you can view current scrontab entries, add new entries, delete entries, and edit entries?
We developed a workflow engine (Drona WFE); it’s very powerful, and it can generate complex workflows. It can also be used for the kind of management tool you are looking for. It would be an interesting case for us as well to see it used in a different environment. You are welcome to try it. We can probably help with creating a scrontab env if needed. It should not take us more than a few days max (unless there are some major issues I’m not seeing yet ).
Here is a link to the GitHub (which is a bit outdated; we are working on more extensive documentation on how to create new custom environments)
We presented an overview of drona at SC25, Here is a link to the paper