I might have confidence in a welded axle-housing but I don’t think a welded axle would hold up.
I base that upon my experience with welded cast-housings which I have repaired myself. I once chained-down the 3-pt of a 9N Ford to keep a trailer I was pulling on a hay-ride from over-running the tractor when going down-hill. That worked just fine.
What DIDN’T work so well was when I forgot the chains after unhitching the trailer .... and I raised the 3-pt lever to the full UP postion....which snapped the lift-arm Upper Forks. Those are made of cast iron or cast steel and they snapped right at the joint of the “U” with the bellcrank.
I needed to use that tractor right-away and used my MIG welder to put them back together. I didn’t notch them out of fear I‘d lose the ability to accurately put them back-together..... (think about breaking a wooden pencil and then putting it back together so-as to appear perfect again)...
I put them together like a pencil and surface-welded them.... and 6 years later they were still fully capable of their original purpose, lifting heavy rotary-cutter/shredder, box-blades, etc. with nary a problem. I’m not certain that would work on a solid axle in the splines-area... but good luck with it.