Without knowing the exact calculations, it's hard to make specific comments. However, I think it's obvious how the interruption death element vs. the eventual worst-case timing convergence death element gives very different results.
With the 0%, you pretty much see a linear relationship between the value of Stamina and the percentage of the delta margin between remaining health and the random variance in the worst case scenario. With interruption becoming the likely cause of death, avoidance gains in comparison to Stamina (in comparison to the non-interrupted case), as they both then provide an effective way to avoid the death condition.
The interesting thing in the chart, which is often mirrored in Burst Time graphs, is the non-linear nature of the value of Stamina in scenarios where it interacts with Avoidance to increase survival. In the case where basically only Stamina matters (the 0% graph) the value of Stamina consistantly drops as the ability to survive N extra death conditons decreases.
However, in the interruption-driven model, while the base value of Stamina relative to Avoidance is lower, it does not decrease in value at the same rate as in the Stamina-centric condition. In fact, you can see the value of Stamina actually increase in many of the graphs where it would have only decreased before. That seems to represent more realistic results, as the effect of adding more Stamina and/or Avoidance is rarely a linear result.
Anyhow, I'm sure the results will evolve with time as you iterate on the testing method. Looking forward to seeing how it ends up and perhaps some more details on the calculations.