A rollback should really be on the table right now. Transactions users per hour is down from 12,000 .. 18,000 to 2,000 .. 2,500 right now and the trend upwards is so tiny it might take till 2020 before we would be back at pre HF20 levels. I think even if a rollback implies losing 3 days worth of transactions, the alternative of basically continuing to lock out 85% of the user base is worse.

Ceterum censeo HF20 esse delendam