Towing with a loaded AF990

Only if you do not make any sharp turns or go through any dips (like on driveways).

I would recommend you get their car trailer instead simply because it has surge brakes. I don't think their dolly has brakes. You already have a somewhat heavy camper.

But either way you choose to go, you're going to have to take a tape measure down and measure tongue length vs. turning radius. It is't that you can't tow either one in a straight line, it's when you go to turn, you don't want corner-to-corner contact.

There are dollies with surge brakes, but I would worry about approach and departure angles on drives pushing the tongue into the underside of the camper and corner contact on any sharper turns.

I have an 18" extension in my garage. Used it twice (then we switched campers)

If you want it, it is yours- just pay for shipping.