Create Agile Gantt-Like Chart for Portfolio

Story: As a C-Level leader, I want a flexible, intuitive chart view at the highest level cross-team initiatives, so that I can selectively expand/collapse any initiative to understand the work, teams, epics and blockers within it.

Details:

• Full screen view showing a bar chart with the name of the top level initiative and agile timeline spanning number of sprints (based on anticipated velocity, exactly as Portfolio currently calculates), with possible dates overlaid if relevant.
• Ability to selectively click into each initiative to dive into the component Epics, then stories, subtasks, etc... (entire hierarchy)
• Clear view of blocking/blocked issues, with indicators (lines?) to what is blocking/blocked by it.
• Clear coloring of issues either by status, or ideally by custom configuration (along the lines of card color logic available on Agile Boards)

Problem this is solving

• Current view makes you choose the overall level (Story Level, Epic Level, etc...), which in larger engineering companies (30+ teams working on large cross-team initiatives) quickly makes it unusable
• Alternate view within current Portfolio is by Project, which doesn't cover the cross-team dependencies that emerge in larger setups or when building a micro-services environment (teams for Database/API/etc... that will play smaller roles in many different projects)
• Current blocking implementation is harder to see (slighter shaded blue) and doesn't indicate what it is actually blocking until you click on it. When you have dozens of relationships like this, that become impractical quickly to visualize where your problems are in the pipeline.
• The biggest alternate portfolio products on the market show views like this, but can't handle the Agile/iterative/points component of the equation. Jira Portfolio DOES handle that piece, and building an agile version of this view becomes a clear delineator in the market.

Note: For the sake of my examples, calling the highest-level issue type Initiative, please substitute as needed.