before better input alterations touching minus.hxx

this gives failure rate about 1-2% on hongyi synth test

Revert "1.9s: slight change, still reliable"

This reverts commit 9ac8865.

version to submit paper

seems unsafe

working before parameter tweak

version sent to Hongyi for testing

tweaks to be tested

num_successes_before_increase = 2-

added threading

Runs in 2s on Ric's computer

first version, 60s down to 9s