Hi @ all,
the thread is old, but you can export a range of the page by setting coordinates.
Specifies the rectangular region that should be exported. Requires the coordinates of the lower-left corner and the upper-right corner in the format: x0:y0:x1:y1. (The lower-left corner of the drawing has coordinates of 0,0.) The units are in SVG user units. Example: to export the left half of a 200 by 100 pixel drawing to a PNG: inkscape --export-area=0:0:100:100 --export-png=test.png test.svg
When you render more than one chart, you can create a output with all charts, or a part of them