I don't know if this is possible, but if it is, it would be helpful if you can add an endpoint for HIVE transfers to the DHF and the resulting HBD. When HIVE is sent to the DHF, it is immediately converted to HBD. However, a virtual operation to track how much HBD it was converted to was added only on 2022-10-11 (see this). So from 2022-10-11 onwards, we know how much HBD was added to the DHF, but we don't know for before that. With the HAF data you have available, would it be possible to get the amount of HBD that each HIVE transfer was converted for?
This will help the Hive Open Stats project. We're working on adding stats to track the DHF balance and incoming/outgoing funds.
Interesting... I will look into it.