Well I'm no mechanical engineer, but I think like one. And I don't think the equalizer between the springs is going do much load equalizing between the two axles.
If it was good at that, you would never have more weight on one axle than you do on the other. And that is not always the case.
So my opinion is ...if the trailer is only a little un-level ( I/2 inch or so, ignore it. But if it is a couple inches difference, I would try to fix it. A couple inches MUST cause un-equal wear & stress.