You could start with a Grid on a Board and select “Create Chart” from the 3-dot menu. This would allow you to leverage the work you already did to make the Grid instead of needing to start at the default Custom View.
You could maybe then make pivots on the Grid and it could affect the Chart. Or it could be unlinked and its own item.
Imagine:
- You have a Chart Card
- You click the 3-dots
- You click “Flip”
- You now see the Grid that is driving the Chart!