OracleDB_0206 custom thresholds

Hello,

I'm trying to monitor an Oracle DB using MP for Oracle.  My DBA wants to define the following thresholds.

MAJOR: 20% of free space percentage

CRITICAL: 10% of free space percentage

The out-of-the-box policy only offers one threshold rule inside.  Therefore, if I need another threshold should I copy the OracleDB_0206.1 threshold defined in the original policy? Should I copy the original policy and make the changes in a new one? If I do that I always receive the following error in the System.txt Agent Log.

Can't find object 'OracleDB_0206' to set async. flag. (OpC20-37)

So, could I use a different copied policy to set custom thresholds?

Why this MP is not provided with more thresholds as other MP like Infrastructure MP which provides different thresholds for Memory, Filesystems and so on.

Thanks in advance.