ai-bookkeeper books a euro credit note against a euro invoice in euros and records the rate difference as a realized exchange entry. A pound credit note against a euro invoice is a different case.
We checked it with made-up documents: a 1,000 EUR invoice booked at 1.10 and a 100 GBP credit note at 1.30. The credit takes 130.00 off in base currency, no exchange entry is made, and a 970.00 payment clears the receivable. That is a reasonable answer, but it is a limit rather than a revaluation, so a test now pins it and the README says so.
The 2027 tax-bracket item is still waiting: the proxy refuses irs.gov. Made-up data only, estimates only, not accounting advice.