TBH, this is the part I’m least clear about. After doing a WF, we get 5 sets of variables … how to decide which to go with? I think the numbers I put in the fixed box (your red arrows) are an average of the OS results. Is that sensible? The parameters are fairly narrow so prob any of those numbers will ‘work’, but which are best? I still have no idea without just going for a general curve-fit!