Rectangular Cuts Issues

Dear Fellow TMVAers,

I am using TMVA for to test the performance of different variables (not more than 2 or 3 at a time) by looking at the ROC curves produced by rectangular cut optimisation.

I have the impression the variable range I provide is not taken into account correctly.
I set:
“CutRangeMin[0]=0:CutRangeMax[0]=400” in the options, make pre-selection cuts so the variable is in that range and also specify the range in the “AddVariable” call.

(I use FitMethod=MC, testing with&without VarProp as well as with&without positive Sigma)

However the Cuts.xml still includes lines like:
cutMax_0=“4.9800691293040165e+02” -> clearly above 400.

Is there any other place where the variable range needs to be specified?

Also I have the impression a SampleSize in the millions is required (for two variables) get a decently smooth curve. This seems a bit much.

Thank You &