You could wait until you get another 500 miles on the truck. However, part of the 500 miles maybe stop and go city driving or short trips to the store. Trust me those mile are harder on the truck than towing your trailer across town.
As for having not prepped your trailer and catching everything before sending you on your way, don't expect this to be your last visit back to the RV dealer. You will be chasing bugs and gremlins for a while unless you got real lucky with your unit. Unless the items that your going back in for are major can't take a trip problems you may simply want to wait until after your first shake down trip and start a list for dealer attention at a later date.
RVing a great, but not problem free. Sometimes you need to be more like Gumby IE: very flexible at all times. And become a believer in Murphy's Law. But, it the end, all is good.