Manual starts are passive monitoring and wont auto crank in case of an aborted start.
Slasher why would you want auto cranking when dry motoring an engine???
The worst case would be the engine would not 'crank' start rotation.
When it comes to carrying out a dry crank procedure the 'Tailpipe fire' is pretty good, other than there would be no need to retard thrust levers and the engine is presumed at zero rpm everything else is correct.
The context of this thread has been to dry crank the engine.
TW