The allowed maximum number of decimals for the Invoice line charge amount (BT-141) is 2.
//cac:InvoiceLine/cac:AllowanceCharge[cbc:ChargeIndicator = true()] | //cac:CreditNoteLine/cac:AllowanceCharge[cbc:ChargeIndicator = true()]
string-length(substring-after(cbc:Amount,'.'))<=2