Creating a subtask is only possible for engineers as we have a special permission on the create step in the workflow for the subtask issue type.
We want to enable the menu-option for converting issues to subtask (as we disabled it some time ago). However: users are not allowed to use this option (as to rule number 1 above)
As converting an issue to a subtask is not the same as creating a subtask, all user can use this menu-option.
Is there a way to prevent this form happening?