I remember seeing this hidden parameter in the past (22.214.171.124) and that had an issue when querying v$temp_extent_map view.
This view returned wrong results if this parameter was set to true.
Now is a different story in 126.96.36.199.
We started to see many ORA-600 [kkqcscpopnWithMap: 0] errors.
Turns out is because of the same parameter.
MOS note “Query Errors With ORA-600 [kkqcscpopnWithMap: 0] (Doc ID 2260457.1)" gives a workaround and a patch to be applied.
After applying the patch no more errors in the alert log.