Separately will take a lot of time : 3 variables = 3* 1-2 hours and we will not see the 3D Graph who is very important

I think as Dow Jones said that it could be preferable to optimize only on 2-3000 comb on 100 000 units and diminish the step after

I really think that more transactions you have in an optimization=more units you have=more probability you have to have the same distribution= Stop max

SeeU