2006 530i N52 (made in 04/2005) with 161xxx miles

I keep getting a 2a87 fault showing up through DIS only (no check engine light), telling me there is a Exhaust Solenoid Stuck/issue. Other symptoms include:

-adding a quart of oil every 450 miles but no smoke produced and no leaks
-RPM surges
-very rarely a misfire-like symptom (new coils/plugs are in)

No other codes.

I cleared the code and then swapped the VANOS solenoids, but the fault still comes up in the 2a87 Exhaust (not the intake), so I am now leaning to the bearing ledge...?

Before I dive into taking this bad boy apart, am I missing anything else?
Would this issue take care of the oil consumption too?
Can it still be the VANOS solenoid?

Basically, I want to rule out everything else before I start taking the engine apart (or is there another way to check the bearing ledge?)

 

Here's some stuff I collected when I got a similar code on my wife's 2009 X5 N52. In my case, the error did go away when I cleaned and swapped the Vanos solenoids.

That is pretty heavy oil usage. If it is the exhaust, that can be replaced individually. Intake bearing ledge can only be fixed with a new head. But, at 160K miles, maybe a new head isn't a bad idea. Not sure what that costs.

 

Thanks,

I have seen this procedure.
so when it say:

...If excessive wear to the camshaft bearing ledge is found, it is only necessary to
replace the camshaft hook ring seals and the affected camshaft bearing ledge.
N51, N52 and N52K intake camshaft bearing ledges and hook ring seals cannot
be replaced separately. Cylinder head replacement requires a TeileClearing
PuMA case

...it means the head should be replaced.
What is PUma case?

At the end this looks like plenty of $$$$$

 

Puma case is internal bmw dealer talk for contacting BMW to approve a big warranty repair