Regex in proxy-redirect-from and proxy-redirect-to

I'm using a complex proxy_redirect instruction directly in nginx and it works, it changes the Location header so that clients are redirected to an ingress for direct connection to a specific statefulset instance. The instruction is this:

proxy_redirect ~^.*\/\/pod-(?<pod_nr>\d+?)(\..*\.svc\.cluster\.local)?(:\d*)?(?<pod_path>\/.*)?$ https://p-$pod_nr.project.example.com$pod_path;

This worked for years but we're moving to using ingress-nginx instead of managing nginx configs. I'm now trying to create the same thing using annotations, so tried the following:

metadata:
  annotations:
    nginx.ingress.kubernetes.io/proxy-redirect-from: '~*^.*\/\/pod-(?<pod_nr>\d+?)(\..*\.svc\.cluster\.local)?(:\d*)?(?<pod_path>\/.*)?$'
    nginx.ingress.kubernetes.io/proxy-redirect-to: "https://p-$pod_nr.project.example.com$pod_path"

However I get these two errors in the logs:

ingress-nginx-controller-59d9446fd6-fv265 controller W1129 16:43:09.772362       7 validators.go:221] validation error on ingress ns/pod-ingress: annotation proxy-redirect-from contains invalid value ~*^.*\/\/pod-(?<pod_nr>\d+?)(\..*\.svc\.cluster\.local)?(:\d*)?(?<pod_path>\/.*)?$
ingress-nginx-controller-59d9446fd6-fv265 controller W1129 16:43:09.773233       7 validators.go:221] validation error on ingress ns/pod-ingress: annotation proxy-redirect-to contains invalid value https://p-$pod_nr.project.example.com$pod_path

Now, I need guidance on why this is being refused while working perfectly in nginx and how to fix it. Tried to use a nginx.ingress.kubernetes.io/configuration-snippet directly but then I got:

nginx: [emerg] "proxy_redirect" directive is duplicate in /tmp/nginx/nginx-cfg3481804691:726

as the ingress controller always inserts a proxy_redirect off; instruction and that is not possible to disable.

Without editing the ingress template directly, how can I implement this?