It depends on the die size. Some hit the center so you can't take as big a bite. But after you take a bite on both sides you can get it in a little farther for a second pull, if needed. The fit won't be quite as good as a cutter type, but you won't get thin edges, either. That's always a problem with cutting tools. If the joint is more for looks, than that's fine, but if it's something like a rollcage, you want to make sure you don't have any tapered edges on the tubing. So you sacrifice a little fitup for more strength. Especially with 4130, if the points are thinned down, you will get cracking there. You never want any reduced wall thickness, especially where the welds are. So even with cutter type notchers, you have grind back any edge taper the notcher left, so you have full wall thickness. I always keep a die grinder handy for final fitup work.
Long arc, short arc, heliarc and in-the-dark!