Rick
This is what I've written about the new IH model in the user manual:
Instead of predicting inharmonicities from the measurements using a theoretical model, pianoscope can also use the exact frequency spacings of partial tones. This mode is active when you set the inharmonicity weighting to 100%.
This mode can improve precision with problematic strings whose partials are difficult to predict. However, for it to bring an improvement, you need to measure the inharmonicity with muted unisons. If you don’t want to spend the time muting unisons, you should stay at the default setting of 85%, which produces good tuning results for most purposes.
So if you have a problematic instrument, it can improve the tuning curve if you re-measure with muted strings. But in the majority of instruments, you don't have to.
Can you describe in more detail when loading takes a long time (and how long)?
