I have a JSON string in a ConfigMap using an ExternalSecret to template in some secrets. All entirely normal.

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: configjson-eso-template
data:
 configjson.json:
    "{\"secret\": \"{{ .clientSecret }}\"}"
---
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: configjson-config
spec:
  refreshInterval: 1m
  secretStoreRef:
    kind: ClusterSecretStore
    name: secretstore
  target:
    name: configjson-config
    template:
      engineVersion: v2
      templateFrom:
        - target: Data
          configMap:
            name: configjson-eso-template
            items:
              - key: configjson.json
                templateAs: Values
  data:
    - remoteRef:
        key: 'client1-clientSecret'
      secretKey: clientSecret

I now need to have another element in the JSON that needs to be the literal string '{{otherValue}}'.
No amount of weird extra quoting or escaping is letting me get that past ESO. I either get some sort of parsing failure, unexpected characters, or an invalid string in the resulting secret.

Using three, instead of two, curly braces results in: unexpected "{" in command.
A single backslash on all four curly braces is illegal for kubernetes.
Two backslashes on all four curly braces is legal, and passes ESO, but the resulting string is \{\{otherValue\}\} which isn't legal to the container parsing the JSON.
'{{'otherValue'}}', and not trying to escape otherValue, just results in ESO trying to go-template it, which obviously fails because ESO can't do that.

How do I make ESO ignore something in mustaches?