We're trailing the use of the built in bug tracking, and have written some integration into our helpdesk software that allows for escalation via workitems.
One thing I haven't found out how to do, is to merge all changes associated with a work item (say to go from dev branch to main) - I appreciate you can double click on a changeset in the merge dialog to view if it is associated with a workitem, and also that I can select individual changesets, and groups of adjacent changesets; but there doesn't appear to be any way to merge changes by workitem?