Thanks for your feedback, there may be some misunderstanding here, yatai-deployment does not rely on the nginx ingress controller, it only assumes that there is an ingress controller available in the cluster, so of course you can use the istio ingress controller. Here is the official documentation for the istio ingress controller, which you can refer to.
https://istio.io/latest/docs/tasks/traffic-management/ingress/kubernetes-ingress/