Thanks for asking! The teams we've worked with do one of two things when deploying Helm charts with ArgoCD. They either pass values directly to the chart from the Application resource, or they use scripts to merge values.yaml files together and pass them to the helm template command to implement the rendered manifests pattern.

In both cases it's tedious to manage the helm values, and they're usually managed without strong type checking or having been integrated into your platform as a whole. For example, you might pass a domain name to one chart and another value derived from the domain name to another chart, but the two charts likely use different field names for the inputs so the values are often inconsistent.

Holos uses CUE to unify the configuration into one holistic data structure, so we're able to look up data from well defined structures and pass them into Helm. We have an example of how this helps integrate the prometheus charts together at: https://holos.run/docs/v1alpha5/tutorial/helm-values/

This unification of configuration into one data structure isn't limited to Helm, you can produce resources for Kustomize from CUE in the same way, something that's otherwise quite difficult because Kustomize doesn't support templating. You can also mix-in resources to your existing Helm charts from CUE without needing to template yaml.

This approach works equally well for both in-house Helm charts you may have created to deploy your own software, or third party charts you're using to deploy off the shelf software.