A little vacuum in the oil drain line and tank in question would help scavenge oil from the CHRA. There are many ways to achieve this.

ex. vacuum canister + Intake suction via pcv valve would store vacuum during wide open throttle and full time during cruise and idle, like brakes have.
It's a bandaid for poor drain from a turbo situation... but the whole rear mount oil control fiasco is a kind of bandaid anyways. Just an idea to make an already complex thing even worse I guess.