Data versioning for (partitioned) external asset?

[MartinHenstridgeImprobable]

Is it possible to attach a data version to an external asset, ideally on a per-partition basis? I've attempted to specify a data version as a tag (with key dagster/data_version, AFAICT this is the mechanism used internally) via both the report_asset_materialization and report_asset_observation REST endpoints, but neither has resulted in a data version be associated with the asset in the UI.

Is this possible via some other mechanism? Or is data versioning, and by extension the caching mechanism, not compatible with external assets?