It really is just the lift arms or draft arms, what ever the proper term is for them, that are the weak link. There should be a way to make them capable of pushing what ever the tractor can throw at them. something like a trucks front plow frame.
Many of these implements are designed to be used in reverse, so no one can say you should never push with your 3 pt. I agree with the snow blower it's kinda pulling itself with the auger, but boxes and blades are designed to push as well as pull the tractors 3 pt systems should be built to handle it.
The rear of the tractor is known to be the heaviest, seems like all that's needed is to make the arms a little heavier.
I installed a truck plow on my 3 pt this year, and as great as it worked I couldn't recommend it to others here in good confidence for 2 reasons.
First, I think I did bend one of my arms a tad, almost not perceivable, but I was ramming snow banks with it, something I said I was not going to do. The rear plow was originally supposed to just be for cleanup after the front loader but it became apparent the the plow was so much quicker and I just used the loader to manage the banks and piles made by the plow.
Second, I thought I might take some heat for making such a recommendation that many here believe to be unorthodox or destructive.
So I won't recommend it to others but I will keep pushing with mine, My lift arms are pre bent right at a critical point making them vulnerable to further bending, just may reinforce my lift arms and be a little more respectful of the geometry.
JB.