OP, your best bet is plop the camper on there and see how much it sags.
If you’re wanting to decide what to do before you drive it on the highway.
The newer F250s have a more compliant, progressive rear suspension. Aka softer ride with no load or light loads, compared to the old lumber wagons.
Since you want to pontificate what’s needed, I’ll say sway bar (that is a given to reduce body roll) and at a minimum, lower stable loads. If you’re truly only 2500lbs all in.
It’ll haul 2500lbs over the axle without bottoming out in normal driving but I’d want to stiffen it up if more than just casual or infrequent driving with a top heavy load.
Being on the edge of the suspension handling it on its own, I’d, again, see how much it sags. Then wedge the springs like lower stable loads and repeat the exercise.
