Currently DOKS comes with a Cilium gateway implementation out of the box. However, Cilium doesn't support proxy protocol to preserve the client IP address. There are plenty of other gateway implementations that do support proxy protocol, but since DOKS comes with the outdated Gateway API CRD's bundle 1.2.1, these alternatives can't be installed (or you need to install a version that is end-of-life). When updating the Gateway API CRD's manually, DOKS cluster updates won't work anymore. So this isn't an option either.

An alternative would be to use a regional network load balancer instead, but these load balancers don't support IPv6.

Any solution would do but preferably DOKS comes with up-to-date Gateway API CRD's.