argocd image updater in argocd write-back method to only download image without changing application state to new image

[UriZafrir]

Is your feature request related to a problem? Please describe.

Perhaps it would be best if there would be an option for argocd image updater in argocd write-back method to only download the image without changing argocd application state?

We have argocd on an edge device connected to internet with SIM. The end solution would have hundrends of them.
The internet there is not always stable and not very fast.
We want argocd to download new images without syncing. this is so that upon approval to sync from a user, the sync would instantly upgrade to a newer image.
So, we want argocd to predownload the image when application goes outofsync.
I can use argo events resource event-source to listen to when the application resource goes out of sync and then run an argo workflow to download new image, and then alert an application pod when the download is complete, and if not retry, etc.
However i'm not sure it's the best way to go because it's error prone with multiple edge cases.

Describe the solution you'd like

Perhaps it would be best if there would be an option for argocd image updater to only download the image without changing argocd application state?

Describe alternatives you've considered

I can use argo events resource event-source to listen to when it goes out of sync and then run a script to download new image.
However i'm not sure it's the best way to go.