All of the libraries and components used by HAast are IPv6 capable, and HAast is designed to accept IPv6 settings. However, due to lack of customer demand IPv6 functionality is not currently tested or certified.
You are welcome to try IPv6 settings with HAast and everything may work. However, we do not officially support IPv6 yet. As of May 2022 we have not had any customer need IPv6 (though a few customers have inquired).
If IPv6 is essential for your implementation Telium would undertake a (for fee) project to certify HAast (only the platform and architecture of HAast you are using). There is not enough overall demand to justify doubling the entire QA process indefinitely for IPv6.
If you are an OEM or volume license customer please contact your account manager to discuss your needs.