No problem, Mike.
And, as an aside-- I always use the boost switch. It is hard to have too many amp-hrs of batteries on startup/hard to have too little voltage drop. In most cases you will more than double the size of the battery bank being used to pre-heat and run the starter.
SO, here is the order:
Turn on boost switch.
Turn key to first position to activate the intake manifold heater.
Start engine.
Release boost switch.
Obviously, if the house batteries are discharged (i.e. you have been dry camping) do not do this!