The "1/2 ton towable" label is just a marketing ploy. Be very careful. Yes, lite-weight/ultra-lite means less substantial construction. Quality and durability suffer.
Just because a manufacturer sticks a "1/2 ton towable" label on it does NOT mean ANY 1/2 ton can tow it. What you need to be concerned about with any trailer is the ACTUAL payload capacity of your truck. Can only be determined by going to a scale and subtracting the weight from the GVWR on your door jamb sticker. Only then should you be narrowing down to what make/model you can tow. That is though, unless you don't care about max. payload and weight capacities stated by the vehicle manufacturer. I don't think one should ever exceed these ratings but many do and take their chances thinking nothing will ever happen.
And you also have to be VERY careful about dry weights stated by the manufacturer. They will always be higher, and sometimes WAY higher. When shopping, use the trailer's GVWR to play it safe. Then use 20% as a guide for pin weight or 15% for tongue wt. Typically a 5th wheel will force you into a larger truck, min. 3/4 ton and up to 1 1/2 tons unless the trailer is a small one.
I know of one manufacturer that has a "1500" line of fifth wheels that are 1/2 ton towable. Their biggest 5-er is 10,800 lbs GVWR making the pin weight around 2100 lbs. After you allow for the weight of passengers, pets, groceries, and cargo, you can be approaching 3,000 lbs of total payload. I don't think many (any?) 1/2 ton trucks can handle that. Our 3/4 ton couldn't. But not to worry, the manufacturer has this little qualifier on their site: "It is important for your safety and enjoyment that your tow vehicle be adequately sized and equipped to tow and handle the GVWR of the RV you select. Review weights and rating of your tow vehicle and consult a competent advisor for questions or advice."