Hi Mellow,
I don't think they get out of adjustment as much as it is luck of the draw as to how they are set at the factory. I wonder if they are set with engine running, or just set to a spec as to how many turns, etc, with the engine not running. I would bet it is the latter and nothing short of fine tuning will correct a generic setting that is not quite perfect.
As I mentioned, the difference in bikes was really demonstrated to me recently when I rode the used 04 at our dealer after riding my 08 there on the same day, same temperature, same road, then getting back on my 08. Major difference. I think that 04 was hotter than my 05 ever was.
There have been a few very interesting posts on this site as to why setting the "starter valves" won't make a difference. In my opinion, there are a lot of theories as to why things won't work, but if you try them, sometimes they actually do work. My "proof of the pudding is in the tasting"" method after owning 3 ST1300s is that the sync is worthwhile and makes a difference with heat as does the counter balancer adjustment with vibration.
On the other hand, as I mentioned above I found the header ceramic coating and wrap weren't very effective for me on my hottest ST1300.