Migration from Helm to Flux Helm-controller

[benke33]

Problem description:

When Flux helm-controller is taking over a Helm-chart installed via other means, Helm install, Helmfile sync etc.
The helm-controller is triggering a "Helm upgrade" to, I assume, add annotations and create Status.History for that HelmRelease object.

Relevant code:
atomic_release.go#L363

Questions:

• Is there a way to migrate to Flux HelmRelease without triggering a "Helm upgrade"?
• Is there some best practices when it comes to migrating to Flux HelmReleases from Helm or HelmFile based deployments?