Mine new banjo's came complete with the replacement oil feed pipe.
Since the replacement turbo oil feed pipe is not expensive when compared to what could be, I just brought the compete pipe with banjo's each end.
As mentioned its some work to replace the turbo oil pipe compared to just the easily accessible top banjo connection by comparison. Also this will give an indication of any blockages once top banjo replaced for inspection. Not to say an issue further down near the turbo could exist!!!
Just to help with our findings regarding reliability.
I still go by doing interim oil/filter changes especially if doing short journeys.
Also Selina oil was breaking down and leaving small carbon like sludge in the oil filler cap and on the dip stick on my car. This oil was checked and oil analysis confirmed suspicions. Thats why I now use Fuchs oil with said interims and not experienced any carbon sludge issues since. Oil now clean and not looking like it came out of diesel.