i would try dumping BSEG and BKPF into a flat file, sanitizing, and uploading them into AWS HANA instance. next, create tables, a join, and analytical view, which in turn can be connected via ODBO to an Excel Pivot table.
if your records are reconciled, your management should see how quickly 100's of 1000000's line items are summarized, especially when compared with the standard SAP transactions like F.01 or similar.
this is not something that SAP would recommend as you would need to upgrade, connect an SLT and eventually migrate (including reconciliation) BKPF/BSEG/COEP to FAGLFLEXA(COEP) and to ACDOCA and maybe use Lumira or Office Analysis to see something similar. i believe there may be some licensing questions that need to be answered first, however, and others may have other ideas.
enjoy the ride!