This is discussed randomly in various threads. Not sure there's been a thread specifically about it??
I guess my first question would be why you think you need it???
In my opinion,,,,, the only gain would be if the tractor is used to pull heavy loads a lot that frequently requires 4wd. Then adding traction weight to the front tires would be valid. For example I pull a 5 yard scraper with my M9540. When loading the scraper I have found it's easier if I first load the FEL bucket. Adding weight to the front tires for better traction while loading the scraper.
My brother loaded all 4 tires on his Kubota L3240. Only difference I saw was his front tires started leaking at the beads and you had to run a lot of air pressure to hold the tire on the rim. Tubeless tires. Rim Guard fluid.
I don't see it as being a hazard to the durability of the tractor. The extra weight isn't carried by the chassis, only by the tire itself.
If the tractor has an FEL, with loaded fronts, you have added a lot of unnecessary weight on the front tires when the bucket is full. No hazard to the tractor. But will certainly cause the front tires to sink faster in soft ground.