I suggest adding support for multiple "modules"/containers inside highcharts main container. Today it is possible to make it work by assigning absolute positions for each y-axis wanted. We are using this in this graph for instance https://www.avanza.se/aktier/om-aktien.html/3873/microsoft-corp (Click settings icon and click "Volym").

The problem today when you want to have multiple containers with different y-Axis assigned to same x-axis is when you want to toggle them on/off (show/hide). That is because axes can not be hidden and we want dynamic shrink/expand main container depending on which "containers" (y-axes) visible. We would also like to have a bar for each container, with label and icons, similar to button bar for main graph but more customizable. Today to make it work, we need to have separated divs outside the container, absolute positioned.