Depends.
When I worked at the building supply place, we sold a bunch units like the one you have. Ours were AgriFab. Part of my job was to assemble them.
The ones I'm familiar with are very light duty units. Fine for hauling grass and leaves, but if you filled it with dirt you'd tear the bottom right out of it trying to use it like a dump trailer. At the very least, I'd build an angle iron subframe for the hoist to push against.
No suspension and cheesy tires too.
I guess what I'm trying to say is that with the unit as is, you'll be in trouble hauling anything heavy enough to make the hoist worth while, and if you modify it to haul denser material you'll have enough invested that you might as well start from scratch.
JMHO, YMMV.