i_limit_job, not _scan.
Plot test statistic, widen ranges.
Don't correlate shape by renormalizing, which pulls off the fit;
eta_bkg more carefully from closure test;
speed up by decreasing eps on root search in BB;
speed up by decreasing n_toy_signif/limit;
if print_level, turn on extra_prints for t(H1)/t(H0);
interpolate for limit with exp instead of pol1.