Dear Julia.

Congratulations for your presentation and paper.

However, in 2016, Enrico Benassi published a similar benchmarking in:

"Benchmarking of density functionals for a soft but accurate prediction and assignment of 1H and 13C NMR chemical shifts in organic and biological molecules"
by Enrico Benassi
Journal of Computational Chemistry, Volume 38, Issue 2, p. 87-92
https://dx.doi.org/10.1002/jcc.24521

In that, he presented the two hybrid generalized-gradient approximation density functionals, WC04 and WP04, optimized for the prediction of 13C and 1H chemical shifts with equivalent errors. 

More information about it:

"Hybrid Density Functional Methods Empirically Optimized for the Computation of 13C and 1H Chemical Shifts in Chloroform Solution"
by Keith W. Wiitala, Thomas R. Hoye, and Christopher J. Cramer
J. Chem. Theory Comput. 2006, Volume 2, Issue 4, p. 1085–1092
https://doi.org/10.1021/ct6001016

So I would like to suggest that you take a look in these papers.
Best Regards.