I have always been in the heavyweight corner, so you can count on me for that.
I know you have a very heavy duty boxblade as it is, so I would give it a shot without the wheels first. I must have ...what... over 250 hours (probably more) using mine without wheels. It worked just fine for me. I think with your box you can cut a lot of "humps" and fill the low spots, but it will depend on what kind of humps.
If they are gradual, over longer distances, I would rip it all first (the high spots) and then drag with rippers up and the cutting edge down into the dirt say 1" or 2" or so to even out. You might even have to back doze those kind to level out. You'll get pretty good results without wheels. But if you had the wheels, after having ripped and filled, the smoothness of grade would be much better with the wheels than without. That is what I'm finding out on my road now.
Now if you got little humps to cut off and little low spots, the wheels would come in really handy because you can cut the humps without having to rip first...especially with your heavy blade. The cutting edge should take care of those small ones and then dump into the small low spots no problem. And I think the heavier the the boxblade, the better it is for the wheel application and the better results.
So it depends on what you got in front of you.