Ah. Yeah. Good stuff. I love learning (or relearning) stuff. Nerds never grow too old to geek out on engineering chatter.
Except that I'm even more confused about what I need to procure in order to lube the splines on the final drive!
On your 2011 1200 camhead--
Most (that I have worked on anyhow) 1200 camhead bikes require as new bolt as they use a micro encapsulated bolt. My official camhead BMW dealer service manual also calls for a new bolt but not a new nut.
To be sure (on YOUR bike) you will have to determine (IF) your bike now uses a microencapsulated bolt or a standard bolt with locking (torque prevailing) nut. Then replace the bolt if it is microencapsulated or replace the nut if it is a locking (torque prevailing) nut.
OR, if still in doubt then just order a new bolt & a new nut then replace both. (this way you cover ALL bases). (new nut is only about $1.10 from BMW)
Or, another option is to re-use your original bolt & nut using Lock-Tite on the cleaned threads (personally I use red Lock-Tite).
The original bolt & nut are not stressed anywhere near their working limits so are basically re-usable many times (as far as stretching & work-load limits go), the reason for required replacement is ONLY due to the nut retention safety aspect.