The break in proceedure I use which is a bit of a hybrid between a couple different methods I only run about 7 tanks total for break in. 6 if I'm feeling lazy but I also only do 1 tank at idle. I know some methods will tell you to do 4+ idle tanks but I just dont see th epoint in doing that many...
Theres a dozen different "break in" methods out there. Some of them call for running one or more of your very first tanks at idle. For bashers I dont think it makes a huge difference what method you use but idling 4 tanks seems excessive to me.