Calculating the loss separately for each simulation shows that fitting the objectives was harder particularly for DSPC at 333K and PDPC at 303K (Fig. : grey curves remain over green curves). Repeating the previous simulation protocol of a DOPC/DPPC mixture at 10/90% mass for Representation 2, we could observe gel/liquid phase separation after adapting the temperature to 288K (10K below the experimental reference). In terms of computational time, here the refinement of 48 bonded parameters of the lipid models using 11 informative simulations required 13 days (wall-clock time) to reach convergence (38 swarm iterations) using 23 particles in the swarm and using 64 CPU cores (each CG simulation running on a single CPU core, scaling horizontally by parallelizing the swarm of particles on an inexpensive CPU machine). Lastly, we underline that experimental data collected for DMPC, DPPC and DSPC in the tilted gel phase (Lβ') correspond to measurements obtained from lamellar bilayers exhibiting non-negligible tilting of the tails with respect to the bilayer normal (~32 degrees) . This tilting triggers a reduction of the hydrocarbon and Dʜʜ thicknesses of ~13-15% in the Lβ' phase with respect to the straight gel phase (Lβ) . Therefore, when evaluating the matching of bilayer thicknesses in between CG simulations and experimental measurements, the optimization protocol here implicitly formulates the requirement that models produce tilted tails for saturated lipids in the Lβ' phase. In practice, not all experimental objectives could be perfectly matched when optimizing the bonded parameters in the context of Representation 2 and we obtain a significant tilting of the tails only for DSPC in the Lβ' phase (Fig. : ~26 degrees at 293K).