I know how difficult it is to support the many wide range of Radeon chipsets. Hans de Ruiter spends many months writing driver code full time for A-EON. AMD's release schedule of new chipsets is continuous and this has forced us to move to Polaris for the next forthcoming driver release.
Credit where credit is due: Bigfoot has done remarkably well here to support the list of cards published in the 3.10 release notes whilst juggling the other development work associated with this large release. We are very grateful for the help and support both he and Frank have extended to us with the X5000 product.