I think using an exhaust fan to suck out the built up hot air in a trailer helps some, but not a lot, with the cool-down time of an AC.
The heat inside a hot trailer comes not just from the air, but from all the contents of the trailer that have collected heat - the furnishings, walls, floor, everything. So when your AC starts cooling, it must remove that heat and deal with the outside heat that is trying to come into your trailer. So it takes a while.
We have found exhaust fans to be very helpful when boon docking in warm weather and air conditioning is not available.
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch