Can I reproduce last month-end's aged debtors?

Open this screen in Saral/accounts/sales/aged-receivables

Yes. Set the as-of date to the month end: invoices paid since are still outstanding as at that day. The figures come from the Xero sync's copy, so the sync time under the title is the report's freshness.

Not what you needed? Inside Saral, ask Kuku (Alt+K) — if it cannot answer, “Ask a human” sends the question to Saral support with the chat attached.