Sorry if this is mentioned somewhere, but it seems you cannot treat a
BLOB SUB_TYPE 1 as an actual Blob? Is this true?

ps.setBlob( pos, newBlob );

Gives me this error:

Caused by: org.firebirdsql.jdbc.field.TypeConvertionException: Error
converting to Firebird BLOB object
at org.firebirdsql.jdbc.field.FBField.setBlob(FBField.java:789)
at
org.firebirdsql.jdbc.AbstractPreparedStatement.setBlob(AbstractPreparedS
tatement.java:732)