macOS Catalina blueoothd high CPU IOBluetoothBroadcomSchedulerWorkaround issue
I've found a workaround: I've figured out MSS probably means Master-Slave-Switch. That didn't suffice to fix the issue. But disabling sniff mode resolves the issue. It seems that some energy management code doesn't work properly. 
The cause of the issue traced down: Apple has a bug within BT3.0 Stack. This issue is not happening with anything BT4.0+.