It’s kind of iffy. I imported some elefont (3d font manipulation program) text and it did lots of weird things. I had to reload it several times and only got it to work by Shift-D’ing it and separating it into a new object. I lost the original file (no big deal, that one) and fretted over the one I was working on (big deal, that one). However, I’m not sure whose fault it was, the dxf format or the elefont program (which is also getting weird). There was some talk in the python forum about the dxf format being purposefully corrupted by its new owner, Autodesk. Do a search on recent topics and I’m sure it’ll come up.
I’ve exported dxf to TurboCAD and have not had trouble so far, but, then, I haven’t done much with it, either.
In short, I would import dxf to a new file and tweak it there. Then, append the object (Make sure it is object, not material or mesh or whatever) into your main .blend file. Hope this helps.