All sources apply for both MWD and rheology data. Refer to the main paper for details on data handling.

- PS1, PS2 and PS3 were originally from the BASF laboratory, and acquired via the Reptate Software (Boudara, V. A. H., D. J. Read, and J. Ram´ırez, “Reptate rheology software: Toolkit for the analysis of theories and experiments,” J. Rheol. 64, 709 (2020).)

- M1, M2 and PScom data was acquired from Wasserman and Graessley (Wasserman, S. H., and W. W. Graessley, “Effects of polydis-
persity on linear viscoelasticity in entangled polymer melts,” J. Rheol.. 36 (1992-05).)

- PSA was acquired from Sugimoto et al. (Sugimoto, M., T. Koizumi, T. Taniguchi, K. Koyama, K. Saito, D. Nonokawa, and T. Morita, “Melt rheology of hyperbranched-polystyrene synthesized with multisite macromonomer,” Journal of Polymer Science Part B: Polymer Physics 47, 2226–2237 (2009).)

- A1PS was acquired from Ferri and Lomellini (Ferri, D., and P. Lomellini, “Melt rheology of randomly branched polystyrenes,” J. Rheol. 43, 1355–1372 (1999).)

- PS8 was acquired from Montfort et al. (Montfort, J. P., G. Marin, J. Arman, and P. Monge, “Viscoelastic properties of high molecular weight polymers in the molten state: II. Influence of the molecular weight distribution on linear viscoelastic properties,” Rheol Acta 18, 623–628 (1979).)