In the spirit of collegiality, following up on this in case folks in similar situation need assistance. Not going into too much details, message me if you want further info...
After various calls to solicitor and banking friends, who didn't know, I finally got a steer from a member of the law society conveyancing committee. It is possible to email a contact in KPMG who can execute these eDischarges.
The law society person flagged re KPMG seeking a massive fee for filing an eDischarge, this turned out true. I don't know the terms of the KPMG contract for managing IBRC post-liquidation, but I imagine Central Bank would not be too happy about these types of charges sought for eDischarges.