expanding OEM line....
....I have never seen a shock hose swell,(And I test them all to see if I could find at least one swell??) when I do any shock replacement or spring swap....
Then you will have to explain two of them that I have had 2002 & 2006 swell up almost like a clown's balloon for making balloon animals.... Both cases were several K before I serviced them. Let me give a little background....
I ride on 25, I ride fast on winding and very bumpy roads. Both bikes at about 20K lost 0-7 for adjustment. I could take the side cover off and watch the hose as I go from 0 to oh, say 14. The line would expand before my eyes for a few numbers once it hit pressure. The line would be very noticeable for growing in length, but it took your fingers to feel it grow in diameter. When the "active" expansion during this activity stops, you are ready to refill with oil and you will be fine for many thousand miles. I did the refill too soon on the 2006, but the 2002 was still perfect 70K after the refill.
Why is this type of line OK for brakes, clutches, and other high pressure jobs? All of those other applications are NOT closed systems like this one is. There is a reservoir to accommodate a new line finding its functional internal volume.
What am I saying about what a tested line will show? If you test a new one, you will not see anything unusual, it has not started yet. If you test a line old enough to have settled in internal volume, you will not see anything unusual, it found its natural final size. This makes it very possible to not see line expansion. Throw in differences in how one rides, where they ride, and what setting they use and it will vary how slow or rapid the OEM line will grow. Mine would grow quickly, thus, my braided line on my 2010.