Also if you trail brake a lot and use your rear brakes 27K may be time to look at pads.
They are VERY thin new. On my 15 RT I jumped the gun as I though my pads were gone until the new ones came and saw how thin they are new.
I am a heavy rear brake and gray clutch area rider, so I do go through rear pads.
On my 17.5 GS, when I just did the 24K service and I replaced them. I have some long trips planned and did not want to have to do it before one of them. They could have went but they were close enough for me to do to not have to worry over it.
One of those trips is 4 days on The Dragon and surrounding roads so I knew I wanted rear brakes in great shape.
Use your GEARS, not the rear brake. Makes a racket but much better control.
Rule of thumb:
10 to 15mph rated turn, use 1st gear.
20 to 30 mph rated turn, use 2nd gear.
30 to 40 mph rated turn, use 3rd gear.
40 to 50 mph rated turn, use 4th gear.
50 to 60 mph rated turn, use 5th gear.
Above 60 rated, use 6th.
Now, that doesn't mean max speed in that gear. It means that gear should give you enough revs to use throttle to trail-brake and also is the right gear for rocketing out of the corner. If you encounter decreasing radius, the higher revs allow you to slow the bike without brakes and turn in nicely.
This is the starting point. In ideal conditions, you can go up one gear. If you find turns are rated really conservatively and the roads are perfect and biting, you can go up 2 gears...but start here and get used to revving the wee out of your boxer twin. It won't break. Ask me how I know.
You want to have some revs when you're turning so you can use the magnificent engine braking that the BMW boxer has on offer. Red line is 7 grand or so. You can use all of it. When you have at least 4,000 RPM, you have gobs of engine braking. Use of some throttle modulation will get you that trail braking rear wheel that you seek.
BTW: I learned this from Edelweiss pro tour leaders. You don't see brake lights when you follow them through the tightest roads in the Alps, even steeply downhill.