Sorry, been away from this for a while. This is for a dashboard (we have many accounts and not all stakeholders have permissions across all accounts, so we need ways to manage the information outside the web console).

I am reluctant to treat ARNs as anything but opaque blobs; I do so when necessary, but I know their format has changed in the past, and the lack of a central resource to track breaking changes across AWS means that we would likely not know that the ARN format is changing until our tools break.

I appreciate the ideas, however, and I'll look more closely at my flow to see what shortcuts I can live with.