Migrating to Rollout: Using scaleDown when applying Rollouts

[sedflix]

When using Rollouts while referencing Deployment, we shouldn't set replicas in the deployment or Deployment would end up scaling on each sync.
But when we do not set replicas in Deployment; on the initial sync ArgoCD syncs Deployment and it is scaled down to 1 before Rollout can start its "scaleDown" function.
Hence, when using Rollots while referencing Deployment with scaleDown, the scale-down function doesn't help if we are doing helm upgrade or applying with ArgoCD.

The only way I found out about it was a two-step enabling process, where I do not remove "replicas" from Deployment when enabling Rollouts. And remove replica after Rollout is healthy.

Is there any other way around it? 🤔

[sedflix]

One option is to set argocd.argoproj.io/sync-wave: "-1" on the Rollout. But what happens if that the first time deployment 🤔 .