A typical workflow for ETFs is defined as follows.
Cash Flows need to exist with effective date <= settle date of acquisition or Client ETF rule begin date, whichever is later.
Trade yield is locked in (stored in trade yield) on the opening trade.
Amortization is calculated daily.
Distributions are entered as Cash Dividends when information is released, presumably backdated to the first of the month.
New cash flows are imported each period, effective the beginning of the period (distribution date-1).
Earnings need to be rolled back to distribution date -1 and replayed to current day in order to reflect the true up of amortization for the current period.
If a previously processed distribution is broken out into separate types, you need to roll back earning to distribution date -1 and replay to current day to reflect the correct amortization.