Level 5th wheel

If it can be made level, then it should be. If it's nose high then the rear axles and tires will be loaded up more than the front - maybe overloaded. No matter the case, it will tow better level.
Dealer is Wrong.

I too would like to know what a little nose high exactly means. A picture would be awesome if possible. Our RV tows a wee tad nose high which is substantially less than "a little". The wee tad I refer to is minuscule, barely perceptible to anyone except my discerning eye.

I would be cautious about any fiver set up towing noticeably too high in the front. It can be pretty hard on the rearward axle and tires.

Cheers!

Mike

I'm guessing it's about 4" high. I think that's too much

Yep. More info needed. A little to you may be a lot to me. More than say 2 inches nose high is pushing it IMO.

Probably need to define a "little". Level is best. Nose high could put more weight on the rear axle. Running level might not give you enough clearance with the bed rails. So you might have to raise the trailer through the suspension. Which could make the steps into the trailer tall.......