The oiling system is often "improved" by putting stainless braided lines which are INCREDIBLY stiff. This causes the oil tank to be shaken by the engine mounted on the isolastics which holds the other end of the feed line.
Even the original herring bone line is very stiff.
Since many people know me to be a contrarialn scientific sort of guy, I use a soft line between the engine and tank, along with a generous bow/loop to add even more flex capibility to the setup. This allows the line to flex more easily and reduce the movement energy transmitted to the tank/rubber mounts.
Less breakage, more reliability is MY goal...bling bling is not...
Remember there is almost NO pressure in these lines (feed or return) so the need for stiff high pressure line is purely an emotional thing not an engineering consideration.