This was how development tried to solve the Swedish ISO20022 format. They did in fact copy the Lithuanian format. But Sweden is not Lithuania. The implemented format for Sweden does not support payments to local banks. If somebody had read the different documentation from Swedish banks they would have understood that. I did in fact send it to PMs some years ago but they did pay any attention to it since nothing changed (they have all left the company).
For Sweden, SERP has only one export format, but it should be one per bank. This since each bank has different interpretations of the standard ISO20022 format.
The code does not support payments including credit invoices correctly either.
Note: SEPA should be renamed to ISO20022 (at least in Sweden). Nobody talks about SEPA, the banks use "ISO20022".