What are you towing? On all of my vehicles, I have a tiedown hole at the front of the frame on both sides. My safety chain fit through that hole without me having to do more than sit on the towbar frame and lean over. When I first got my dolly, I knelt down on the ground in order to fish the chain through, but soon learned that I didn't have to do that. The only thing I have to do is take the "D" ring off of the chain to fit it through the frame tiedown hole.
The safety chain is the safest setup, although cables and proper straps are ok. My chains were rated for 6,000 lbs and came with my Roadmaster.
Again, after learning that I didn't have to crawl under or kneel on the ground to connect my safety chains, I was happy with that setup.
I changed toads to a rear wheel drive and no longer have my dolly. That is the only reason I got rid of it though. I now tow 4 down with a towbar. I'm happy both ways.