Burgy I have to disagree a little bit with you...
On the E39 M5 there were various MAPS for limp home mode, depending on the fault picked up by the DME the MAP of limp home mode was choose, for instance, the three MAPS I can remember offhand were one for vehicle speed not allowed above 60km/h, more than one for engine revolution limit and the third was a combination of the two.
You are right though, if one switch the car off and wait a while till the fault goes outside the limp home mode parameters the engine will operate normally till the next fault trigger the limp home mode again.
On the E39 M5 I got a few limp home modes which limited my revolutions as well as speed due to to high engine intake air temperature, this was caused every time I sat in slow traffic and at the end I figured it was the heat build up inside the engine bay which caused this. The car spend weeks at BMW to try and find why it went in Limp home mode but BMW never found anything wrong...
I do not know the conditions of trigger for limp home mode of the OP specific car but I guess it might well be a similar trigger for limp home mode depending on the severity of the fault condition.