How about a Data Layer that somehow gets additional data on your current visitor – on the fly – without your developers having to implement anything?
Welcome to what Tealium calls “Data Layer Enrichment”. We use it e.g. for more accurate long-term metrics, Facebook Retargeting with better privacy, deciding which qualitative surveys a user gets to see, Cross-Device Tracking (limited), and it helps us knowing how many block 3rd-party cookies.