How to make the Charts module use the Highcharts legend option "useHTML" (required for RTL)? I tried using the Charts module with Highcharts as my charting library (engine). And this for a block view in a multilingual site that flips between LTR and RTL.

I found out that the legends and tooltips break in RTL. The legends labels overlap the colored boxes and the text within the labels is pushed outside of the tooltip box.

I managed to make the tooltips presentable through the use of $chart['#tooltips_use_html'] = TRUE; (in 'chart_alter'). Although the text is aligned wrongly the out of box issue disappeared.

However I found no similar option for the legend. I looked at the Highcharts documentation where I found a useHTML option for fixing this issue with legends. But I am unsure about how to apply it with the hooks provided by the Charts module.

Here is a picture of it:
You should be able to get this to work using the approach as described in the issue about Pass library-specific options via existing #raw_options, AFTER you apply the patch in comment nr 4 of this issue.

Disclosure: I'm a (co-)maintainer of this module.

PS 1: Would be nice/great if you could confirm that this patch also worked for you.

PS 2: after a similar patch becomes available to Google charts also, both patches will be committed.