I would advise you to use your own judgement.
My experience is that I had our Yamaha 3000 mounted on the tongue of our first Oliver
and it will be mounted on the tongue of our new Oliver
. At 165 lbs it didn't move for 6 years. I ran it there for hours and never got a whiff of exhaust. Yes, I know CO is odorless but the other gases are not. Anyway, everybody has a CO detector, right?
It sat right beside 2 x 20 lb propane
tanks and will sit beside 2 x 30 lb tanks from here on. The tanks, however, are enclosed within the fiberglass compartment made for them.
At less than 60db, I can hardly hear the generator running from the inside of the trailer and do not feel any vibration. I toyed with the idea of ducting the exhaust away from the trailer but found that I didn't need to.
I don't think this setup is very different from running in sitting on the tailgate of a pickup.