Very good, and yes not much harm on wamr starts, but depends on how much everything is cooled.
The Oil is the main thing, and depending on what grade / age oil you have depends on how fast it will drop below effecient operating temperature for component protection etc etc.....
However, has everyone forgotten that no matter if your water temp is up, thie does NOT mean your oil is up to operating temperature.
Also it you let it idle for a while then go out and drive it hard, your diff and tranny oil is cold!!!!!!!!!
All I can say is, NO BOOST and below 3000 untill a good 5 mins past normal water temp.
BMW have a good model, and enyone who has driven an M3 E46 will know, the ECU wont let you rev the engine above 2500at absolute cold, then slowly dials in more revs as its gets warmer..
IMO!
M-Jay