Excellent video Whizbang. One should also remember that video even when adding air to tires. Many of us have 80psi D or E load range tires on our rigs.
If I was going to try to weld the center with the tire on it, I would let the air out, remove the valve stem, and weld a little at a time and let cool.
I never thought about welding my Hyundai space saver rims for my CRX, as they looked really really strong. My car runs about 150 mph, and I was never even asked about it at Bonneville tech, and yes, they knew what rims they were and did look at them.
I've got some more rims to mount different size tires on. I will weld them before I do so. Only 10 minutes with the MIG.
Jeff