Separate question, I have a metric which is a duration metric which is currently calculating as the total time divided by all the ppl who started the experiment to show me the average, but I would like it to show me the total time divided by the number of ppl who triggered the event (e.g. in my case “Time To Assessment Completed”). How would I do that?

I haven't tested this with Mixpanel, but there's a metric setting to only include converted users. That will ignore everyone with a duration of 0 or undefined

yup that works, thanks!