The oil damp ventilation system is a good example.
Despite the original part from BMW is quiet efficient in condensing oil damp, it’s a bit too restrictive for high revving engines.
Worst case it can even build up some pressure. Sometimes creative individuals use 2 of those parts but you can hardly call this a beautiful solution.
We have chosen to completely remake our previously welded alu tank. So practically it means remove the bottom, install a bulkhead and add a huge exit tube. On the exit we placed a small K&N filter so we avoid dirt and dust coming in.
The standard red screw top we still use but it has no added value breathing since it is much too restrictive.​