My first comment is.....Thank you for including a picture. That really helps in understanding your concern.
Unfortunately, Ford and other auto manufactures, don't use the same protectants on their truck frames as with other body parts. Rust is a common problem on truck frames.
You mentioned that you picked up your PC in January. The chassis might have gotten winter salt spray when delivered to the PC factory and/or on your way home from Elkhart. I don't know how far you live from the gulf, but I have family in Florida who live near the ocean, and their vehicles are a wreck from the salty sea air. Maybe your rust is simply from the humidity of the area.
Regardless of how it started to form, the rust is just begiinning. Now is your best time to do something about it because it will be very easy to stop it with minimal labor.
There are a number of products on the market to stop the rust from continuing, without having to remove it. I'll share my own experience when tackling severe frame rust with my Ford Ranger pickup truck.
Four years ago I bought a 1996 Ford Ranger with only 44,000 miles. I got it for only $2000 because of rust issues. I removed the bed to expose the majority of the frame and spent a few nights banging off loose flaking rust. The rust was very bad, but caught just in time to save it. After all rust layers were banged off, I applied two coats of a product called
POR-15, then one coat of Rustoleum paint
Fast forward 4 years to today, my pickup truck frame is still rust-free. Understand that my truck is my primary commuting vehicle in the Chicago area where winter salt spray is a very serious matter.
If you go to that website, they talk about a preparation product, actually an acid. Your rust is so minor that you can apply POR-15 right on the rust in your picture without any kind of preparation. POR-15 penetrates the rust just like a penetrating oil. Be careful not to get any on your skin because it will be there until your body sheds that skin.
