Not an expert but it makes some sense that a big reservoir of oil lower down lets you lower the top level although I think a lot of lubrication is actually achieved by the moving parts chucking it about alongside the pump feeding it to the more remote bits.
Something to beware of is the way they ask you to extend the oil pickup pipe by pushing a slotted metal tube over it and clamping with a jubilee clip, I could not see how that would ever fully seal so it must suck oil in through the joint as well as from the bottom of the sump.
I have thrown that away and got a length of steel pipe connected by heat and oil proof rubber tube. This also helps you align the pickup in the strainer, an absolute nightmare with the solid connection tehy supply
Now we are back to the old scenario of do you want to corner, dump the sump of oil into a rocker cover, and suck air through the pipe joint? Sort of defeats the object of a deep sump anyway.
An ordinary sump still whips up oil droplets so back to the thread on breather boxes

My setup is a breather box and deep sump.