Safty chains

Even with 4 down towing you are not going to get rid of the safety chains. You may not have to under so far, but you will still be on the ground hooking them up. If you find a way to hook them up without getting on the ground let me know, I too am finding the ground getting lower and lower every year.

Would a small stool work. You could sit on stool and reach under with arm to connect. I use a small stool for brake work for the same reason, getting harder to get up.

My baseplate has the safety chains attachment points right out in front. Four down I find to be an easy way to tow IF you got the right vehicle. 4 wheel drive for simple shift to neutral transfer case, No locking steering wheel so you do not leave the key in and have to pull fuses, Lite weight to avoid aux braking systems, separated tall light system.

I do not get on the ground and it takes about 6 minutes to hook up and go.

My vehicle is a 2012 gmc Colorado 4 wheel drive. Love it

I am going to modify my attachment plates so the cables snap on right out front. I would take the vehicle to a welding shop and have them do that for you. Make it easy on yourself.

I would lose the dolly and the unneeded handling of it both before and after hookup. Use safety cables rather than chains. Purchase the spring loaded and operated latches at the hardware store.
Get them large enough to do their job properly in case of a breakaway.
And yes!! By all means go to four down towing. Maybe you can get enough out of the dolly to pay for most or all of a new 4 down tow setup.