Excel for Windows has supported adding Shapes inside (not over) Charts for many years. Excel Online does not (if a Chart contains Shapes, they will not be displayed) Would it be possible to support...
My team also needs this feature. In our case, we want to add text boxes/shapes directly to a chart and then group them within the chart itself (see idea posted here: Inserting/ grouping textboxes with Excel charts. We need this functionality in Office.js and Excel Online. Without it, we can't modernize our Excel VBA add-in to Office.js.