Hi there,
If you look at the _shouldDropEvent method, on line 43, you can see it calls and evaluates the return of _isSameMessageEvent as well as _isSameExceptionEvent in that order in order as part of evaluating if an event is a duplicate.
I can’t speak to all non-Error promise rejection events (you will see that we don’t recommend filtering this phrase outright) but I have seen good results with upgrading to 6.9.0 in resolving the high volume errors when they are related to the MSFT range of IPs.