I wouldn't be going as fast as Marcos does his engines (each to his own though <grin>)
With a new engine I open it up and remove any metal filings left in there from when it was made (yes it happens)
I then drop some lube down the glow hole and fit the plug.
The engine is then pre-heated with a hair dryer, this will make the engine a lot easier starting the first few times and reduce stress on conrod/crank pin.
Once engine is started you can either idle, heat cycle, drive around slowly whatever takes your fancy but you must not rev the engine as this puts lots of stress on engine.
A good way to check if engine is ready to be leaned out and dialed in for racing (ie you can start reving its tits off hehe) is take glow plug out and turn engine over by hand. Once you feel only *slight* resistance you can lean out, otherwise keep on with the low revs/break in process.
Just remember all engines are different, how long break in takes depends on the materials and the size the piston/sleeve from factory. IE, a STS Dragon will take 2 Ltrs of fuel before its ready to be leaned out, yes unreal hey. Rush it on a Dragon and you have high chance of busting the crank pin off the crank...