Create internal structure or density variation based on fem analysis of the model, to create stronger parts with less infill. This might seem too much to implement, BUT keep reading, it might actually be doable. In the article referenced bellow, it is stated how 2d fem analysis in 2d can be used for augmenting infillpatterns to create better strength to parts.
Using finite element analysis to influence the infill design of fused deposition modelled parts Gopsill, J.A., Shindler, J. & Hicks, B.J. Prog Addit Manuf (2018) 3: 145.
Why is this useful?
Other slicers for FDM printers does not do this, some commercially available closed source slicers for SLS might however.
Beside the link to above article, nummerous open source project exists for FEM analysis. Herunder is an exert from the article. Picture is covered by Creative Commons, see article for correct attribution.
Infill designs generated from the predicted planar stress profiles of parts (from: )