I got to D-4 in the SMAS version in one playthrough (sadly, didn't beat it), without using the unlimited 1-ups trick with Mario. Of course, that's with 5 starting lives. I haven't played it in a while, so I don't know if I could do the same with Luigi. I should try it on the Wii VC version for authenticity, I suppose. Or the GBA Famicom Mini version, that cart's collecting dust someplace. I've played through the whole game a couple of times with both Bros. on the SNES and GBC versions, at any rate, but not without continuing.