Small Multiple Line Chart with Auto-Adjusting Y-Axis

Trying to show growth in similar groups of people but with vastly different sizes means that showing them on the same line chart tends to hide trends in groups with smaller numbers. There is a custom visual Small Multiple Line Chart which starts to address this by being able to split one chart into several by a specific factor, such as Country, but the Y-axis is static across all of the small multiples so the problem persists where, say, a country with a small population will have an almost flat meaningless trend line if it's in the same dataset as a large country with a high population because of the scale. I'd like to see a standard visual developed to allow small multiple line charts but where the Y-axis can be set to either be fixed (as in the custom visual) or auto-adjusting so that each small multiple might have a different range to allow trends in smaller populations to be seen more clearly.