Just to add some information from BMW Documentation to the thread:
Two oil pumps are installed in the S65 engine; the oil return pump, which is driven via a gearwheel by a crankshaft, and the volume flow-controlled main oil pump, driven via chain drive by the oil return pump.
In the S85, the VANOS high pressure pump is installed instead of the S65 oil return pump, and the S85 oil return pump is contained in a housing together with the main oil pump (tandem pump).
Since there is no space to install a tandem pump in the S65, the oil return pump has been moved from the main oil pump housing and installed instead of the VANOS high-pressure pump. This allows the pump drive principle (crankshaft => gearwheel => pump => chain => pump) to be maintained. As in the S85, the volume flow-controlled main oil pump is a hinged-valve oil pump with a feed capacity adjusted to suit the VANOS low-pressure system.
The duocentric design of the oil return pump ensures that oil is always available at the inlet pipe of the main oil pump in the rear area of the oil pan, i.e. even when braking sharply from high speeds.
The electrical oil return pumps installed in the S85 for scavenging the cylinder heads are no longer required, which results in a further weight saving. This is made possible by the lower number of cylinders, modification of the oil return routes, and the large capacity of the oil pan.
The oil pan has a capacity of 8.3 litres (S85 9.3 litres). The oil supply is also guaranteed at extreme longitudinal and lateral accelerations of up to 1.4 times the normal gravitational acceleration.
Given this design, I think that the oiling system is definitely up to the task.