I can't say for sure about all OEM rubber brake hoses from BMW are this way, but the hoses on my '81 R65 and '02 oilhead did not have an inner liner, only single thickness rubber, without any fabric braid in it either .
I'll see if I can find one of the hoses from the '82 LS, cut it open and post a picture .
The line from the master cylinder to the splitter, broke on my '81 R65 after 10 years, that's whan I went to braided stainless lines, they were less costly than OEM lines at the time in 1991 .
In 2007, I replaced the OEM rotors with EBC semi floating steel replacements and EBC ' organic ' pads, I think they are some sort of graphite material FA57 pads, if I'm not mistaken .
Dry braking was not noticeably improved, but wet braking was greatly increased, to where I will not hesitate to ride it in wet conditions, the OEM rotors and pads were unsafe in wet conditions from my experience .
This is the one area that I would like to see an improvement in, after getting off of the oilhead, or '87 Guzzi, the R65 brakes aren't confidence inspiring and I've had my '81 R65 since January, 1981 .