I think that you might be mis-understanding Oak's point. My interpretation, and what I have heard from other sources, is that you want the engine to get hot, and
then cool down WHEN IT IS IN YOUR GARAGE or wherever you work on the bike, as the clearances will change alot during that first heating/cooling cycle.
You want the bike to be where you are going to work on it and do the head torque and valve check after the bike has cooled off overnight, before you restart the engine a 2nd time. This way, if things have REALLY drastically changed, you won't run the risk of damaging anything, oil leaks, etc. the 2nd time your start and run the bike.
If you go ride the bike to the mall, shop for an hour or two, ride to the hardware store, stop for 20 minutes, ride to the ice cream shop, and then back home, you are subjecting the bike's engine to multiple heating/cooling cycles, which is what they are telling you to NOT do on that first ride/cruise.
The specification of the torque values from BMW are for a cold engine. I would not try to torque the heads to those specs when they are hot, not to mention
avoiding burned fingers !
