[Schulisco]

Concerning the change from rubber/poly lines to steel lines I can suspect that this was related to the fuel pulsations by the fuel pump, still touchable when engine is running, the fuel accumulator flattens them, but obviously not enough. They also increased the volume of the FA over time also on other cars. Some people claim that surging engines could be cured with the steel lines. Porsche transferred experiences from the 930 to the 911..Also they will last much longer. Don't forget that a correct pressure is key on a CIS...
E.g. the fuel lines on other CIS cars like an Audi 4000CS / Audi 90 Type 81 from 1985 has steel braided fuel lines...I suppose that it's related to heat stress as they're mounted on top of the engine and above the exhaust manifold and secondly due to the fuel pulsations.

I have no secured information on the CSV flange if it matters to mount the CSV with or without the flange. What I know is that Porsche struggled on blown airboxes when starting the engine. Porsche claimed the CSV as the culprit because the fuel sprayed did not distributed evenly on every intake runner. Instead the fuel enriched those intake runners first sucking the air which leads to backfires and blown airboxes. Therefote Porsche introduced the spider. Probably the flange was introduced before the spider to manage a better distribution of the fuel before they introduced the spider. Also the air line coming from AAR and intake boot helps mistifying the fuel.

Thomas