I think that the DialogSelectThresholds() method is closer to working now in that it properly publishes sensible thresholds.
I think that the original code had a bug which prevented proper analysis: the accession identifier column wasn't properly named in a manner that it was visible to the computation.
I'm NOT completely sure, though, that the filtering process is properly applied to the input data. I will still have to single step through the code to see if it is working exactly as expected, to filter out the input values within the user-specified range.