Hello,
You can use SVGRenderer to generate custom
dataLabels for series but first you have to move each group of hexagons to a separate series and set
series.name for them.
Demo:
https://jsfiddle.net/BlackLabel/2r8fLsdh/
API:
https://api.highcharts.com/class-refere ... VGRenderer
Let me know if you have any further questions!
Best regards!