UK geomap Rendering

I am having trouble mapping out data using the UK Counties geomap.

Currently I have a post code value that is split, then looked up to a few variations of the recommend highcharts pointers.

I have stumbled upon the issue though that skuid is only pointing the field at “postal-code” with has a null return for about 15-20% of the counties. There is also a problem with overlapping within some of the "postal-code"s. 

Is there any way to change the point to either “hc-key” or “hc-a2” as they are unique by county? 


Raw js for reference


I believe the Hicharts county code for UK is the HASC code,  not the ISO 3166-2 code.  Here is a reference for HASC codes:

This does not seem to be an officially sanctioned standard and so I worry about it changing.  But it should provide a reference for your Postal conversion lookup.