Well, you can try. Wrap the broken area tightly in electrical tape (preferably white or yellow so it doesn't absorb a lot of extra heat from the sun and cook under there). Extend the tape a couple of inches each way from the break if possible. Then, try to prop the branch so that it's weight isn't putting pressure on the break. This is probably all you can do, IMO. It may or may not work. Even if it does survive, it might be prone to breakage in the future from this. But, you probably don't have a lot to lose, so you might as well try it.

Make sure the electric tape doesn't wind up girdling the whole tree. When it starts to get too tight you can use a razor and make a single slice, test the branch and if it still needs support tape again. You will save the branch if it has enough connecting tissue to give it adequate sap which would already be apparent. As the trunk grows it will wrap the branch with new tissue and in a couple years- good as new.

I hate those 4-1 trees because varieties have such variance of vigor. Better to make your own 3 in 1 by grafting up a central leader (Christmas tree shape) making each of 3 tiers a different variety starting with the most vigorous cultivar for the lowest tier. It's my own secret method (which I'm sure others have also discovered).