BMW isn't the only one to use an oil separator. Many OEMs use both a PVC system which pulls intake manifold vacuum on the cam cover during light throttle applications. When you go full throttle and there is no vacuum, there is another, separate hose that vents the cam cover to the intake tube post MAF. Vacuum on the intake tube exists when vacuum in the manifold does not and visa versa.

BMW added the separator in part to control how much vacuum is on the crank case and when, in addition to not coating the intake tube, throttle, and intake manifold with so much oil. It really is a great idea in theory and largely works.

My idea is to leave that in place and install a "failsafe" vent hose from the cam cover to the intake tube with a check valve so that only if the OEM valve cover vent is plugged (due to frozen sludge, stuck CCv, whatever), this hose would prevent crankcase pressure from building up and massive amounts of oil from entering the intake manifold.

As engines get older and develop more blowby, the problem will only get worse.

I'm open to other ideas but that's mine.