For WF 28, go through the list of @Deprecated items in the key server kernel modules, remove any uses found in full or core and remove as many as possible.
I expect this JIRA will serve as kind of epic, with separate JIRAs filed for specific items or closely related groups of items.
Items to handle can be seen here:
I'm open to people filing issues for an taking care of specific items and linking them here, particularly for things that are completely unused (both in core and full) and have been deprecated since 2015 or earlier. Please leave changes to widely used controller module classes to experienced kernel developers.