Mark,
I certainly wouldn't try to smooth the existing texture as you will be inviting many rock chips on your first trip. IMHO take it to a shop that does "rhino coating " type work on RV front ends and have it "touched up as needed. I had 3M "diamond shield on my 2 previous RVs and hated it. It does "chip" and peel at the larger chip areas, regardless of what the ads claim and is a "monster" to remove. I had my front cap repainted about 18 mos ago due to an accident and left it unprotected. I plant to "rhino coat" it when it gets enough chips to make me have to sneak up on it.
Steve