I would like to create a report or dashboard widget for management where I could select the Legends, Initiatives, Epics I want to report on and then show high level data such as total story points, story points closed in last sprint, story points remaining, project completion. The Field - Progress (story points) covers the first and third of these as a progress bar but I would like to show the value.
if you're open to solutions from the Atlassian Marketplace, you may like JXL for Jira.
JXL is a full-fledged table/spreadsheet view for your issues that, among many other things, allows grouping and summing up your issues by any issue field. It also respects parent/child relationships between issues, so you can model very powerful (real-time) reports.
This is how it could look in action:
Note that you can model almost any issue hierarchy, and view (and inline-edit) any issue field (including custom fields), so this really just one example. More info at https://jxl.app. Disclaimer: I work on JXL :)
Hope this helps,
Best,
Hannes