It’s a very simple formula where there’s a value assigned to each variable then it’s simply : Metrics to improve x Expected improvement x users affected x Frequency / Story points.
You can potentially try assigning different set of values to each multiplier to the variables.
Keep in mind that the numbers in isolation don’t mean anything. They’re only useful when compared to one another since the purpose is to prioritize the stories.
Please do keep me updated if you use this tool with your team. I’d love to hear your feedback!