Is it possible to execute a raise notice without the "Notice" keyword being part of the output, or is there another construct that allows writing to output as simple informational text (without any sort of NOTICE, WARNING, etc being part of the output?
I am not sure if I understand to query well. If you ask on possibility to set a level of RAISE statement as dynamic parameter, then the reply is not.
The log level - DEBUG, .. NOTICE, WARNING, ERROR is required field of PostgreSQL log/error processing system.