Makes complete sense... so are the instructions below wrong? (I've also included the link of where this is posted). The method you described is also mentioned.
Re: Cam Chain Tensioner -- Unoffical Manual
Tensioning the Chain - Automatic adjustment with engine running
This is the factory procedure, and should work fine with an engine in good working order.
1. Idle the bike until it's warm (warm enough that it'd burn you if you touched it, i guess)
2. With the bike running, loosen the adjuster nut, wait a few seconds, then re-tighten it. Don't overtorque it. Just snug.
3. If the noise is worse than before, follow manual procedure below
http://www.hondatwins.net/forums/62-engine-discussion/16966-cam-chain-tensioner-unoffical-manual-450-s.html#/topics/16966?page=1