I am fairly sure this has been discussed before, and might be mentioned on the wiki page too...? The reason for the back-to-back flashing is to make the device create aegis keys with open mode. That will help with some problems you might have with Harmattan later. It is possible you will have no issues but some people have had those, hence the recommendation for back-to-back flashing. No reason to be, noobness is something that is easily cured