Hmm, tend to agree with your friend. Off the top of my head
Your cockpit locker will fill up with petrol fumes when you fuel
up the genny and since they are heavier than air they will stay there until you switch on the anything electrical
in the cockpit locker, like heating
or battery charger
, or even the genny itself.
Next what about the exhaust
, its going to make an awful mess inside that locker which someone is going to clean up at some point in the future. If there is a problem are you going to climb into a nearly enclosed space thats full of carbon monoxide, thats the silent lethal gas btw.
We have a portable genny and yes it is a bit of a pain lifting it out every time, but please play safe with fumes sparks and exhausts.