not knowing too much about the custom layout of your setup,

normally oil should be fed to the turbo via a hard pressured line from the back of the drivers side head, the volume of oil in the line is tiny, so highly unlikley oil is ingressing via that route.

the return line is normally gravity fed back into the sump via the bottom of the drivers side head also, although in your case i think you have a pickup pump circulating the oil back into the sump electrically? if so, providing the pump is evacuting all the oil both during operation and after your engine is shut off then you shouldnt have any pooling or return pressure issues, that is of course that the return point of oil into the engine is higher then the cold oil level of the engine.

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