Does ρ help?

Yes. Without ρ, the estimated margin reads too low while the specimen is intact. With ρ, it is right. Once the specimen is damaged, both agree.

with ρ without ρ true margin damaged unsafe below 0.38

Average error, all eight cases

Estimated minus true margin. Below zero means the estimate is too low. Click a bar to open that case.

Specimen intact

Specimen damaged

One case over time

Margin

Adaptive factor λ