Need a new feature in WAF v2 custom rule to process IPv6 address

I have created a custom rule to allow traffic based on the Geo Location. The rule was designed to check the location of the actual client IP coming in the Request Header and deny if it is from non-UK region. This rule blocked genuine request from UK region since the client IP was an IPv6 address. WAF custom rule has a limitation of processing IPv6 address. https://learn.microsoft.com/en-us/azure/application-gateway/ipv6-application-gateway-portal#limitations 

Need this feature of processing IPv6 address in WAF custom rule.