We have lots of workflow transitions that required certain custom fields to be populated, implemented using the excellent Jira Suite Utilities plugin.
The only limitation of this plugin is that the required fields are not marked as mandatory on the workflow screen, as the fields made mandatory by the project's field config are (red asterisk in Jira 4.4). The plugin developer has this issue closed as "Won't Fix", because it isn't possible to change the screen layout from a plugin
Is anyone aware of an alternative method that will provide the same functionality, but also have the field displayed as mandatory? Or are Atlassian planning to add plugin developer tools to do this?