If the change is to a Kubernetes field (such as modifying a Deployment attribute), it will likely need to be install-time configuration.
However, that doesn't necessarily mean a PR to add a value will be accepted.
The `values.yaml` API is intended to maintain a *minimal core set of configuration* that most users will use.

  optional SubjectAccessReviewStatus status = 3;
}

// SelfSubjectAccessReviewSpec is a description of the access request.  Exactly one of ResourceAuthorizationAttributes
// and NonResourceAuthorizationAttributes must be set
message SelfSubjectAccessReviewSpec {
  // ResourceAuthorizationAttributes describes information for a resource access request
  // +optional
  optional ResourceAttributes resourceAttributes = 1;

    - [RBAC](https://docs.projectcalico.org/v3.2/getting-started/kubernetes/installation/rbac.yaml) - this creates the service account the CNI plugin is configured to use to access the kube-api-server...

  optional bool readOnly = 3;
}

// HTTPGetAction describes an action based on HTTP Get requests.
message HTTPGetAction {
  // Path to access on the HTTP server.
  // +optional
  optional string path = 1;

  // Name or number of the port to access on the container.
  // Number must be in the range 1 to 65535.
  // Name must be an IANA_SVC_NAME.

* For large API changes, 2 members of the TOC must approve the PR before release manager approval in the release branch
  of the istio/api repository. This does not have to wait for the weekly TOC meeting.
    * Risk should be assessed in the PR.
        * Have installs and upgrades affected by this feature?
        * Is the feature still being worked on?
        * Is the default behavior altered?
        * Is this turned on by default?

roles to manage different parts of Istio. For example, a security team would maintain the
root CA and policy, a telemetry team may only have access to Prometheus,
and a different team may maintain the control plane components (which are highly security sensitive).

The install is organized in 'environments' - each environment consists of a set of components

  // to determine if Kubernetes should modify ownership and permissions of the volume.
  // With the default policy the defined fsGroup will only be applied
  // if a fstype is defined and the volume's access mode contains ReadWriteOnce.
  //
  // +optional
  optional string fsGroupPolicy = 5;

  // tokenRequests indicates the CSI driver needs pods' service account

  // "*" matches all verbs. If it is present, it must be the only entry.
  // +listType=set
  // Required.
  repeated string verbs = 1;

  // `nonResourceURLs` is a set of url prefixes that a user should have access to and may not be empty.
  // For example:
  //   - "/healthz" is legal
  //   - "/hea*" is illegal
  //   - "/hea" is legal but matches nothing
  //   - "/hea/*" also matches nothing

  // "*" matches all verbs. If it is present, it must be the only entry.
  // +listType=set
  // Required.
  repeated string verbs = 1;

  // `nonResourceURLs` is a set of url prefixes that a user should have access to and may not be empty.
  // For example:
  //   - "/healthz" is legal
  //   - "/hea*" is illegal
  //   - "/hea" is legal but matches nothing
  //   - "/hea/*" also matches nothing

  // traffic only if the traffic matches at least one port in the list.
  // +optional
  repeated NetworkPolicyPort ports = 1;

  // from is a list of sources which should be able to access the pods selected for this rule.
  // Items in this list are combined using a logical OR operation. If this field is
  // empty or missing, this rule matches all sources (traffic not restricted by