Problem

When concatenating multiple Plots via PdfPages (from backends.backend_pdf) I am interested in having a proper table of contents navigation in the sidebar of my PDF viewer (I first posted this question here). As far as I can see from the code this is neither possible out of the box with the current implementation, nor easy to "hack in" during runtime.

Comparing the adobe reference (section G.5), one would need to add the outline keyword as well as titles for the respective pages (coming optionally from pdf.savefig in PdfPages or similar).

Unfortunately I'm a bit overwhelmed by the code and not sure if I can contribute this. Please let me know if some extension of the functionality like this is appreciated at all and I'll dig more into this then and see what I'm able to achieve here.