Eric - the notes rather over-egg the jackstall recovery - you have to pull quite hard to get it into jackstall and then only a slight relaxation of that pull is required to let it recover.
You have to keep pulling hard to keep it in jackstall which is a very un-natural thing to do.
The danger is getting it in a right hand turn, especially at low level as it rolls you further right as it enters jackstall.
We used to demonstrate entry and recovery either in a left hand turn at IPS or in a dive to VL at MPS.
212 - agreed, but that funny (peculiar not ha ha) loss of 'lip-lift' can give you a slightly more binary effect as Nr decays.