I have Line-X on the bed of my truck. The local installer had a trailer, and a BUNCH of other equipment, all coated with their product. Amazingly tough stuff.
That said, I use the snot out of my truck. I noticed recently that I have quarter sized dents in one fender well. The coating shows no signs of peeling, and I think I can knock the dents out. But in no way does Line-X hide the dents of this size. If the dents are dime sized, they might be able to apply enough material to fill the low spots. Might cost more due to more material, and might add significant weight.
I suggest taking your trailer to the local shop and let them give you an assessment.
And not to start a debate over which product is better, I did a lot of research before going with what I bought. Some products fade badly after a few years.