hettest is an R package to test for a treatment effect using surrogate marker information accounting for heterogeneity in the utility of the surrogate.
More details on the method are available in Parast, L., Cai, T., & Tian, L. (2023). Using a surrogate with heterogeneous utility to test for a treatment effect. Statistics in Medicine, 42(1), 68-88, doi:10.1002/sim.9602.
Go here to view a tutorial for this package: hettest Tutorial. We also have a shiny app implementing this method here.