i think you'd have to experience pretty bad surge to empty a 6 pinter into the sump TBH.
as said. mine (4 pnt) seems to hold 2 bar or more of oil pressure when the engine is turned off for about 10-15 seconds ... so for surge to last that long... thats a pretty serious corner!

Unsure if with engine on it will still supply 2 bar for that long though?? would the crank rotating make a difference?

EDIT: that said, like a lot of car related mods.. some people seem to get alright results, others dont!
and to 'test' a system like this,, your only gonna know if it dont work once!! lol