I borrowed a torque multiplier kit like the OP has from a fellow MV collector to do the wheels on my truck. It's geared 64:1 and rated at some ungodly amount of torque on a 1" drive. I used that to break the clamp ring nuts loose on my A3 rims and borrowed a strong DeWalt 1/2" impact to get them the rest of the way off. Before I was able to borrow the impact, I 3D-printed a solid ABS 1"x1/2" square drive adapter so I could run the multiplier with my 10-amp DeWalt impact drill (with the impact mode switched off, of course!). That combination was pretty zippy!
My preferred use now is to break stuck nuts off with the multiplier after chasing threads with a die. For installation, I use a strong impact wrench to zip nuts on, then set torque with the torque multiplier. It's easy to do the math for the proper torque wrench setting, and with the high gearing you can set torque with a little 1/4"-drive torque wrench - just convert ft-lbs with the gearing to inch-lbs!
Just be sure to factor in 15%-20% slop from the planetary gear set in the multiplier and apply it to the torque setting. I checked slop by slightly tightening up a clamp ring nut with the multiplier, then using my Armstrong 600 ft-lb torque meter to loosen it and measure the loosening torque.
The only thing I wish I had in that torque multiplier is the ability to use the ground with the reaction arm instead of an adjacent lug nut or rim wall, like the older military ones. If someone made that I'd buy it.
