Ok, this avoids the error. But it's not very nice in terms of using SQL, as it automatically truncates the output:
select n from testtbl;
N
jybzvndzvqmhsjaatgyoupbwmvfcumqzeolnaivactmcdubanwhgktnqtvzzesikndskrbuzthmncgdu
So I would prefer to use varchar2(2048). It outputs the complete value then. And as I have carriage returns in it, it's output with some formatting as well.
As I mentioned, setting the Param size explicitly in that function in Aurelius that cannot recall right now did prove to be a solution. So, can you either bubble that setting up so it can be set programmatically by the caller per field, or just set it automatically in your code if the field is Oracle/varchar2()?